Should we evacuate elderly people in a nuclear or radiological accident?

There is an interesting talk on the ICRP’s ICRP Digital Workshop: The Future of RP by Jessica Callen-Kovtunova entitled Making ICRP Recommendations ‘Fit for Purpose’ for the Response to a Nuclear or Radiological Emergency.

In this she reports a meta-analysis of 600+ papers which reviewed the impact of protective actions and claims that for every 1000 people evacuated we may expect 7 deaths among the general public due to dislocations caused by the protective action and between 15 and 117 among residents of facilities for long stays and the elderly as well as between 120 – 220 mental health problems.

They compare this to 5 deaths prevented by evacuating 1000 people with an averted dose of 100 mSv each (this appears to be based on the ICRP-103 approximation of the overall fatal risk coefficient of 5% per sievert).

They conclude that: “Taking protective actions consistent with dose criteria used in many countries could result in far more excess deaths than hypothetical excess radiation-induced deaths prevented.  We must include these effects to protect people effectively.”

If we agree with these findings, and before doing that I’d like a closer look at the applicability of the evidence, we must ensure that the current ERL for evacuation is reconsidered and its application to homes for the elderly, in particular, given very careful thought.

If we start to think about different protective action thresholds for different age groups maybe we could also consider stopping planning to give those over 40 -50 years old stable iodine.

The potential for remote inspection in the nuclear industry – Webinar

I’ve just listened to a Webinar “How to Implement Remote Inspection in the Nuclear Energy Sector?” organised by TUV SUD (I’m not sure about the question mark!).

It introduced the idea that one person could “walk the site” wearing smart glasses, while their colleagues watch from a remote location, request the walker stop to look at anything that catches their attention and ask questions through the walker. If accepted, this could complete an inspection with fewer on-site resources and will generate an audio-visual record of the inspection from which the report and conclusions can be written.

I’m not sure this is a particularly new concept; the nuclear industry, and probably others, use remote monitoring to support operators working in difficult areas where there is a balance between having all the skills and expertise to hand and minimising the size of entry teams. The use of smart glasses may be new and maybe adds another option to body worn cameras and infrastructure mounted cameras. The application to teams of off-site inspectors may be novel. The service offered seems to be the full sweep of technology, hardware and software, from the camera to the remote inspectors; with the lessons of experience and training offered as well. This may well be a unique service for the time being but barriers to entry are probably not high.

There were several questions to do with broadband signal, band width, data protection, cyber security and safety with the conclusion that this technique is well within current technical capabilities. It has been used maybe 10 -20 times in Europe and about 50 times in China.

This is an interesting concept and an area that is likely to develop in future. Why send a team of people to a remote site and then into an industrial or contaminated environment when you can send one person, or a robot?

The regulators would have to consider the qualifications and experience required of the on-site inspector, who would be much more than just a camera operator, and the conduct of any such inspection. The industry could consider if the technology has application in normal operations and accident response that adds to the capability already offered by site sensors, including cameras, and body worn cameras that they already use.

22/9/21

IAEA Technology Roadmap for Small Modular Reactor Deployment

IAEA Nuclear Energy Series, No. NR‑T‑1.1

Technology Roadmap for Small Modular Reactor Deployment

We hear a lot about the potential for Small Modular Reactors, Advanced Modular Reactors and microreactors to provide reliable, affordable, low carbon energy to produce electricity, district heat, industrial heat and hydrogen, including in places where grids cannot reach but, other than in China and Russia where they are getting on with the job, generally the discussion is about getting to the demonstrator (or First of a Kind (FOAK)) rather than beyond.

The stated objective of this paper by the IAEA, drafted by an international group over a series of meetings, “is to present several model technology roadmaps to Member States which can be adapted to their specific projects”. The guidance “describing good practices, represents expert opinion but does not constitute recommendations made on the basis of a consensus of Member States”. It is notable that no one from RR, ONR or BEIS was on this group.

The authors keep interrupting the narrative about how to plan for the deployment of SMRs with seemingly random sections reviewing the state of play with various designs across the world and the history of the field.

The paper is apparently aimed at:

  • owners/operating organizations, who drive the demand and requirements for reactor designs;
  • designers, who develop the technologies; and
  • regulators, who establish and maintain the regulatory requirements that need to be met by owners/operating organizations.

Technology roadmaps, we are told, “are part of a methodology that guarantees the alignment of investments in technology and the development of new capabilities. A proven management tool, technology roadmaps are used for identifying, evaluating, communicating and promoting the development of complex technology projects”. One aim is to increase the chances of passing well known pitfalls where failure is more likely (Figure from IAEA NR-T-1.18).


The first pitfall is the potential failure of the R&D to satisfactorily addressed all technology gaps to enable the construction of a reliable prototype or the performance of an important proof of concept test. (I think that technically competent reactor designs fail at this stage due to a lack of funds to continue). The second is commercial; is the technology reliable, accepted by the regulator and cost competitive against its alternatives?

The operation of an SMR or a fleet of SMRs requires national soft and hard infrastructure such as:

  • Physical facilities for the delivery of electricity [or heat];
  • Site and supporting facilities for handling and disposing of radioactive waste;
  • Legal, regulatory and policy framework;
  • Financial resources necessary to implement the required activities;
  • Trained human resources.

In fact, the paper recognises 19 infrastructure issues (Table 2 of report). This is a useful list. Civil servants looking at government support for this technology should review this list to see if it identifies any expensive or difficult hurdles.

One of the issues with SMRs is the potential for them to be built rapidly – several a year – with the potential for deployment in countries other than those in which they were designed and built. These two factors present a challenge to site licencing which is much discussed.

For countries that already have a nuclear industry the hosting of a SMR or fleet of SMRs should not pose great legal, regulatory or infrastructure issues although the siting requirements may need further consideration as with potentially reduced emergency planning zones and less cooling water requirements these plants can go on a wider range of sites. It would also be necessary to consider the county’s ability to manage the fuel cycle and waste produced by the SMRs if they differ from the existing fleet. The paper gives an update on progress in several countries.

For countries without an existing nuclear industry the IAEA has outlined an approach in an earlier paper (Milestones in the Development of a National Infrastructure for Nuclear Power, IAEA Nuclear Energy Series No. NG‑G‑3.1 (Rev.1)). This involves stages before a knowledgeable commitment can be made to nuclear power; before they are ready to invite bids from suppliers and before they are ready to commission and operate the first power station. Each of these stages are discussed.

It is interesting to consider how this might apply to the Russian concept of floating power stations where the extreme view could be that the licensing, safety and fuel cycle issues are all managed by the Russian company to their national standards and the host country has an electric cable running into from offshore. How different is this to a French PWR providing power to the UK via a cable running under the English Channel?

Section 3 of the report is a review of the prospects for SMR technology which the IAEA rate as promising. Section 3.2.4 seems to suggest that public are certain to accept the technology because it is the only way to hit the IPCC’s decarbonisation target. I am not convinced!

Section 4 identifies stakeholders of which the keys ones are the designer/supplier, the owner/operating organisation, the technical support organisation, the investors, the regulatory bodies, the government and the public. It then discusses regulatory frameworks including the IAEA and OECD/NEA and WENRA and discusses goal setting and prescription as the two major licensing approaches before introducing the SMR Regulators’ Forum.

Section 5 concentrates on near term deployable SMR technology and provides a road map in three sections: owner or operating organisation, designer/vendor of the technology, regulatory bodies. This section is very disjointed and hard to read.

Section 6 looks at more innovative reactors designs which are further from market and highlights technical areas and R&D activities that are likely to absorb effort and funds on the pathway to deployment. This section also reviews six technologies that are being considered and takes a speculative look at the potential integration of renewable energy sources with nuclear sources.

An annex to the report reviews three designs of SMR in operation or under construction.

This could be a very interesting report but the drafting is poor making it hard to read from beginning to end. It does however give an impression of the breadth and depth of work that is required to support a nuclear power plant. I’m sure that it could be useful to a civil service providing government funding and support to the SMR industry. What would be useful is a map showing the development path for SMR and AMR reactors with a series of gates through which they have to pass, a discussion about what needs to be achieved before a reactor design can pass each gate and the technological and financial risks implied, who is responsible for the risks and an estimated cost and time for reaching each gate.

Streamlining the licensing of Small Modular Reactors, WNA Webinar

 

WNA webinar

I watched the World Nuclear Association webinar about streamlining the licensing of Small Modular Reactors on July 28th. This was an interesting event with some good speakers. It is currently available on-line here.

The grumble behind the event is that, while companies want to sell their reactors around the world the pesky regulators in each country they want to build in want their say on the suitability of the design and this is tiresome, time consuming, expensive and may lead to country-specific design changes. The speakers made a good case that their jobs would be easier and that SMRs could start generating energy sooner if the regulatory barriers were at least lowered. We were also told that this is important for decarbonising the world energy market which is a relatively new way the SMR companies are trying to lean on Governments.

The audience was challenged by Tom Bergman, Vice President of Regulatory Affairs, NuScale (a leading SMR design/build Company from the USA) with the question “Do you believe that a design approved in the USA is not fit for somewhere else?”. Maybe we could ask him if he would be happy for a British designed reactor, approved by the British regulators and built in Britain to be operated in his backyard without US inspection of the safety case, design, build and operation? We also heard from Sol Pedre, Manager of CAREM project, the National Atomic Energy Commission, Argentina (CAREM is a simplified PWR being built in Buenos Aires province) who, rather naively in my opinion, thought that if they could build and operate a reactor in Argentina then that should go a long way to convincing other regulators that the design is safe enough for worldwide deployment.

Nadezhda Salnikova, Head of Business Development Department of Afrikantov OKBM, JSC, ROSATOM (this is the company that designs and builds Russia’s nuclear propulsion projects such as submarines, icebreakers and floating nuclear power plant) commented that they produce plant for use within Russia under Russian regulatory supervision but the floating power stations can go anywhere. A lack of global licensing means extra work for the Company and work for the local regulators that may be beyond their capabilities.

It was suggested that new nuclear nations could simply accept the regulatory approval of the country selling the reactor. I suspect that this runs counter to IAEA expectations but might be acceptable if a floating plant was to be temporarily positioned following some crisis and operated by experienced staff. This is little different to a nuclear-powered submarine or ice breaker visiting a foreign port.

I have some sympathy for the potential loss of design stability caused by local requirements. This potentially makes the design chain and build more complex but we are talking about an industry that, according to the IAEA had more than 70 SMR designs running in 2020  (Ref. here) while NuScale have designed 50, 60 and 77 MWe versions of their reactor before building any. Design updates do not seem to be a particular problem. Meanwhile modern flexible manufacturing systems should enable slightly different builds to be accommodated on the production lines without reducing shareholder value too far.

The problem with attempts to produce global standards is that most countries agree with the concept providing that the world adopts their existing standards (hence my question to Tom Bergman above).

This event did not really explore the barriers to closer working of the regulators across the world and the advantages that might accrue from converging regulation. I would be interested to see a  comparison of the regulators. What do they do in a similar fashion? what do they do differently? How much scope do their national laws and guidance give them to meet in the middle? Why would they want to do this? How much of the licensing effort is based on design and how much on siting, building and operating? Knowing this, we might then be in a better position to move partial streamlining of international licensing from an aspiration to a realistic target. (This information may be available in the WNA report “Design Maturity and Regulatory Expectations for Small Modular Reactors” which I haven’t yet read in full).

Small Modular Reactors are often based on evolutions of proven technology with enhanced levels of safety built in. Much of the additional safety comes from the small size and layout of the plant greatly reducing vulnerable pipework and reducing dependency on active systems for layers of safety. They have reduced the number of systems (valves, pumps, filters, tanks, chemicals, switches etc) that need to be considered. It seems logical to assume that their safety cases are simpler and fewer systems means fewer things to understand and approve. Design approval should be quicker.

Importantly the construction takes place in factories, possibly in a foreign country. What expectations will the regulator have for quality control and will they require to inspect the reactor during build?

If governments wish to see SMRs contributing to low carbon electricity, district heating, process heating and hydrogen production in the not-too-distant future then they do need to encourage regulators to do their bit to hasten the process without compromising safety. Generic Design Assessment (GDA), which takes about 4 years and is not mandatory, is far from the only issue. They also need to consider how the licensing of sites and operators will be undertaken if the market penetration talked about comes to pass.

What will the siting requirements be? Currently the UK process spends a lot of time and effort considering if a particular site is suitable for a reactor. That may be acceptable if you are only going to build one or two sites a decade but we cannot expect, for example, a foundry to spend years of effort to get permission to use a small (or even micro) reactor to melt metal. What siting processes do we need if, for example, six reactors are going to built and deployed each year?

In the UK the ONR has recently announced new guidance for parties requesting Generic Design Assessment of SMRs and AMRs (Advanced Modular Reactors). It would have been interesting to hear a discussion of this guidance, and the strategy behind it, to see if it goes someway to meeting the aspirations of the reactor manufacturers.

The UK 10 point plan calls for demonstrator SMR and AMR deployment in the early 2030s. But what is the strategy to deploy them, including siting them, in the following years?

I started listening to this webinar thinking about the issue of using one design of reactor in several different countries but ended up thinking that a more difficult issue (in the UK) may be that of gaining public and regulator acceptance of many more nuclear reactors doing a wider range of jobs requiring them to leave their large, well-protected sites, in the countryside with their hundreds of well qualified workers and instead sit in one corner of an industrial site or in the outskirts of a town and with a much smaller staff. This is  a national, rather than an international, issue.

I’m grateful to the WNA for organising this webinar and for the speakers who gave their time. It is an interesting topic and was well presented. A good case was made that life for a reactor vendor would be easier if some of the regulatory barriers were streamlined. It was not made obvious that this was likely or even possible. The question in the webinar title was not answered.

 

 

 

IAEA EPR-Medical Physicists 2020 – Guidance for Medical Physicists Responding to a Nuclear or Radiological Emergency

IAEA EPR-MED

https://www.iaea.org/publications/13483/guidance-for-medical-physicists-responding-to-a-nuclear-or-radiological-emergency

In the event of a nuclear or radiological emergency hospital medical physicists may find themselves providing front-line response to the event or supporting their hospital’s efforts to triage and treat potentially contaminated casualties.

The objective of this IAEA publication is to guide the trained clinically qualified medical physicists (CQMP[1]) to act appropriately in a nuclear or radiological emergency and ensure that an efficient and coordinated contribution is made to the management of such an emergency. The knowledge of the CQMP can be vital in the preparedness and response to nuclear or radiological emergencies.

The report is accompanied by a pocket guide which summarises most of the concepts given in the full report and is designed as a working aid. But at 78 pages it would require an unusually large pocket. Rather than be an on-the-day aide-memoir the pocket guide covers a lot of preparedness information from the main report. EPR_Pocketbook_web.pdf (iaea.org)

The main report starts with an introduction to emergency planning giving various definitions of emergencies and then a quick overview of the roles the medical physicist might occupy in the local and nation emergency response plans. The noted roles are:

  • Radiological assessor (RA) requiring a qualified expert in radiation dosimetry;
  • Scientific and technical advisor giving advice on matters related to a nuclear or radiological emergency;
  • Trainer in radiation protection providing training within their own clinical environment and, possibly, within and beyond their hospital. During the emergency the trainer will be able to provide quick briefings on radiation protection to the emergency teams.

The medical physicist may serve in a pre-hospital function supporting triage teams and decontamination actions or in the hospital providing advice and training to medical staff.

I think I would have preferred the report to start with what a nuclear or radiological emergency might look like to hospital staff: many people turning, some injured, some contaminated (some both injured and contaminated), many worried well. This may better grab the reader’s attention.

The concept of a scalable incident command system, allowing multi-agency coordination and rapid decision making over a range of scale of event and the medical physicist’s position in the chain of command are discussed. The importance of each player knowing who they report to and to whom they are responsible in a crisis organisation and the understanding that this may not align with normal management is stressed. The diagram given here, cut and pasted from another document, is not helpful. Showing the medical physicist’s position in a chain built round them might have been better.

In section 4, the report runs through the preparedness phase tasks of risk assessment, training, criteria for exposure, potential roles and responsibilities, personal protection and radiation monitoring, procedures for donning protective clothes & monitoring. This section is not a model of clarity and covers material that a medical physicist might be expected to know.

Section 5, which covers activities related to the response, sees the medical physicist implementing the hospital emergency response plan and ensuring that the facility is protected. They will provide briefings on radiological protection and what may occur during the handling of contaminated patients and they will ensure that proper arrangements are followed to minimise the impact on the hospital resulting from the presence of contaminated patients. This section comes with a useful flow chart tracing the possible pathways to treatment for casualties with different combinations of needs, a list of equipment that might be useful and a list of possible actions (including a flow chart showing different actions assigned to different roles in a coordinated manner).

There is also a section labelled the radiological control of areas which is cut from another document and outlines the demarcation of areas for different purposes and the control of people moving through the system to minimise the spread of contamination. Maybe this material should be in the planning section.

Section 6 is entitled early dose magnitude estimation and decontamination. It suggests that accurate dose assessments are unnecessary in the response phase of an emergency; what is needed is a magnitude assessment: is there a problem with either external radiation or contamination that must managed along with the casualty’s clinical needs?

The report discusses how to assess external radiation dose and reviews the gamma ray constant and inverse square law which will probably not be new to many medical physicists. It also mentions a few computer tools such as the Rad Pro Calculator and the Radiation Emergency Medical Management (REMM) dose calculator which are useful to have available.

There are some tables showing how radiation dose can be deduced from observations about which symptoms show and how long after the exposure they show. Versions of these tables should be in the hospital’s emergency data set.

The report suggests that “Internal radiation doses can be extremely complicated to determine” and that “The aim of the assessment of internal contamination is to quantify the incorporation of radioactive material into the body and to estimate the committed effective dose and, where appropriate, the committed equivalent dose to demonstrate compliance with dose limits”. I think that this is appropriate for individual cases of internal contamination following operational mishap but is wrong in the context of responding to a nuclear or radiological emergency. Here the purpose would be to determine what, if any, medical care the casualty might require because of the exposure.

There is a short section on decontamination of casualties. I am sure I have read better.

In the section on the protection of the public (Section 6.2) the report mentions using plume models etc. to estimate deposition levels but gives no clue about how to manage the results. It also talks about determining isodose curves around sealed sources to help the determination of public external exposure.

The collection of excreta for radionuclide analysis is mentioned but no details of the assay methods or reference to dosimetry models used to estimate dose.

After the initial crisis stage there may be a requirement to improve dose estimates. Section 7, which discusses this area has some “key considerations” and some equations but little in the way of practical advice. Maybe following the references quoted may prove more helpful.

In Section 8 it is argued that Medical Physicists should “enhance their communications skills, so that they can contribute to the timely dissemination of relevant information and contribute, all with the response team, in managing individuals and professionals involved in nuclear or radiological emergencies”. You might have thought that these skills, as opposed to speaking to worried members of the public, came with their job.

The psychosocial aspects of nuclear or radiological emergencies gets a sub-section but this does little more than point to further references.

The rest of the section is a very brief overview of communications skills.

Section 9 is a more helpful section on the contents of a “grab and go” bag. This includes dosimeters (EPD and badges), survey instruments, protective equipment, data sheets and forms and miscellaneous tools.

Section 10 gives a very detailed suggested syllabus for training medical physicists and reading lists which are predominantly IAEA publications and would need a fairly large bookshelf to hold and some considerable time to read.

Appendices provide more detailed advice on reception area layout, tags and forms and summary of OILs and reactions to their exceedance.

This is a potentially useful document for hospitals when considering their plans to cope with a nuclear or radiological emergency and considering how to use their radiation specialists. However, it is not only very uneven in the level of detail given but also does not seem to have considered what skills and knowledge the radiation specialist already has and where they might need some training.

It could be better.

[1] See IAEA Human Health Series No. 25, “Roles and Responsibilities, and Education and Training Requirements for Clinically Qualified Medical Physicists”

IAEA Handbook on the Design of Physical Protection Systems for Nuclear Material and Nuclear Facilities

IAEA NSS 40TA new IAEA publication has been published (May 2021) (link here) . This has the objective to provide comprehensive, detailed guidance for States, competent authorities and operators to assist them in implementing the recommendations from the IAEA on the Physical Protection of Nuclear Material and Nuclear Facilities. This area is subject to the Convention on the Physical Protection of Nuclear Material (link here). The UK signed on to this, with some reservations as a member of the EU. I cannot establish the current position.

A Physical Protection System (PPS) is an integrated system of detection, delay and response measures. It should comprise people, procedures and equipment to provide defence in depth, with a graded approach, to address the range of threats identified in the applicable threat statement and to protect against both unauthorized removal and sabotage. The PPS comprises interior and exterior intrusion detection sensors, cameras, delay measures, access controls devices and response measures.

The handbook recommends a systematic design and evaluation of the PPS with requirements identification, design, and evaluation phases. These stages are each explained in some detail. This process is fine if you are starting afresh on a new site but, with an old site, you are more likely to be trying to combine systems with a range of ages and technologies into a workable and justifiable system. The principles need to be modified a bit for this circumstance.

The handbook advises on how to deter an attack on a site by making potential adversaries think it an unattractive target because of low probability of success or high risks to themselves.

There are detailed sections on physical protection systems (design, evaluation, testing and technology options) and the management systems required to keep it all operating effectively.

This handbook would be a good read for any security manager and security systems designer.

Dirty bombs and malicious source placement

There are a couple of reports of interest to local authority nuclear emergency planners in a recent Journal of Radiological Protection (Volume 40, Number 4, December 2020). These are part of the European Commission’s CATO mission which “proposes to develop a comprehensive Open Toolbox for dealing with CBRN crises due to terrorist attacks using non-conventional weapons or on facilities with CBRN material” (https://cordis.europa.eu/project/id/261693).

The first comes from the Belgium Nuclear Research Center with Carlos Rojas-Palma as the lead author (Carlos Rojas-Palma et al 2020 J. Radiol. Prot. 40 1205). This reports on a series of experiments in which mocked up Dirty Bombs of a variety of designs were detonated in urban-like environments. These used a number of tracers to represent the radioactive elements and a variety of detection and measure techniques to record the dispersion.

The report is constrained by security concerns so is unfortunately a bit coy about some of the important details.

Following a ground level explosion activity was found up to 5 m high on nearby walls and that the activity on the ground at 30 m was about 5 % of that at 9 m. They concluded that most of the dispersion was ballistic rather than turbulent. Whereas that might be true in this case, or even in most cases, it might not always be true; it could be assumed to depend on the physical form of the radioactive source and its packing and the force, temperature and geometry of the explosion.

The authors state that, in this instance, the radiological red zone would extend beyond a 50 m perimeter but, without any idea of the effective source strength and the blast being published the value of this observation is greatly reduced.

The paper suggests that any aid or movement of severely injured victims would ideally be performed by personnel in full protective equipment.

Airborne radiation levels can remain elevated for tens of minutes. This is affected by the weather conditions and the layout of buildings. Respiratory protection should be considered for anyone working in the red zone.

The levels of deposition on dummies placed in the vicinity of the blast suggest that decontamination will be needed for people within 50 m of the blast and monitoring, prior to release or decontamination, for those further out.

Deposition on walls was significantly lower than that on the ground but it is suggested that a thorough decontamination of the surrounding area would be needed to satisfy public demand.

For a device detonated in a car the distribution of ground deposition was rather random, making surveying and reporting harder and more time consuming. It was suggested that the fraction of radioactivity remaining in the vehicle would pose difficulties for forensic investigations.

This is a limited report of a series of careful experiments. It is to be hoped that the full results are available to, and explained to, the relevant emergency planners and first responders.

The second report, also with Carlos Rojas-Palma as the lead author (Carlos Rojas-Palma et al 2020 J. Radiol. Prot. 40 1286), discusses retrospective dosimetry to assist in the radiological triage of mass casualties exposed to ionising radiation. It suggests that the outcome of a terrorist event could be mass casualties with radiation exposure of individuals ranging from very low to life threatening and in numbers that surpass the capability of any single laboratory. Thus, it argues, an international network of laboratories would be needed. The European RENEB network is such a network (according to their website at http://www.reneb.net/ PHE is a member). A paper outlining their objectives is available at http://dx.doi.org/10.1080/09553002.2016.1227107.

This report discusses a series of exposure experiments with a 0.65 TBq and a 1.5 TBq Ir-192 sources, a bus and a collection of water-filled canisters and anthropomorphic phantoms. Detectors included a range of TLDs (Thermoluminescent dosimeter), OSLs (Optically Stimulated Luminescence) and body-temperature blood samples.

The project achieved three things: measurements of the doses that could be accrued by people sitting on a bus near an unshielded radioactive source, an inter-comparison of the reading of dosimeters by different laboratories and the evaluation of newly developed retrospective dosimetry methods. “Retrospective dosimetry” allows the doses of accidently exposed people to be measured after the event and can be used to inform the medical care they receive.

IAEA Integrated Regulatory Review Service (IRRS) visits ONR

In October 2019 there was an IAEA Integrated Regulatory Review Service (IRRS) visit to the UK. Its report can be found <here>.

The IAEA state that: “The Integrated Regulatory Review Service helps host States strengthen and enhance the effectiveness of their regulatory infrastructure for nuclear, radiation, radioactive waste and transport safety.

IRRS teams evaluate a State’s regulatory infrastructure for safety against IAEA safety standards. The teams compile their findings in reports that provide recommendations and suggestions for improvement, and note good practices that can be adapted for use elsewhere to strengthen safety. Mission reports describe the effectiveness of the regulatory oversight of nuclear, radiation, radioactive waste and transport safety and highlight how it can be further strengthened”. <here>

Prior to the visit the UK authorities conducted a self-assessment and presented a preliminary action plan and supporting documents. The IRRS team, which consisted of 18 senior regulatory experts from 14 IAEA Member States, 2 IAEA staff members and 1 IAEA administrative assistant, and 3 observers, reviewed these and a number of other documents before their visit and then spent two very busy weeks in the UK. This included interviews with 16 regulatory bodies and governmental departments.

Of particular interest to me are the references to emergency planning.

The mission commented that the “emergency planning zones established under REPPIR 2019 are not fully in alignment with the requirements of GSR part 7”. They recommend that the “Government should review the UK EP&R framework to explain how the requirements of GSR Part 7 are met in terms of planning zones and distances, and if any gap exists develop appropriate regulatory requirements”.

We must remember that GSR part 7 is IAEA advice and its section 2 states that it is “established in addition to and not in place of other applicable requirements, such as those of relevant binding conventions and national laws and regulations”. It goes on to say that where there is conflict between the GSR-7 and other requirements “the government or the regulatory body, as appropriate, shall determine which requirements are to be enforced”. I would expect that the ONR would have to champion UK regulation over IAEA advice.

We know that the UK “planning zones” do not match those of the IAEA. The UK zones have developed over many years and have, in the past, suited the UK emergency planning framework. REPPIR-19 was an opportunity to undertake a review of planning zones but it was an opportunity missed. The current system of a DEPZ with a torturous definition and an arbitrary outline planning zone does nobody any favours.

GSR-7 defines a precautionary action zone (PAZ) where arrangements are made to implement urgent protective actions and other responses before any significant release in order avoid or to minimize SEVERE DETERMINISTIC effects. This is severe accident territory and a release profile consistent with older designs of contained reactors for which a containment failure after several days of heating up was conceivable. So the PAZ as described in GSR-7 does not seem to make a great deal of sense in the modern world.

The next IAEA zone is the urgent protective action planning zone (UPZ). This is an area where arrangements have been made to initiate urgent protective actions and other response actions, if possible before any significant release of radioactive material occurs, on the basis of conditions at the facility, and after a release occurs, on the basis of monitoring and assessment of the radiological situation off the site, in order to reduce the risk of stochastic effects. This is broadly similar to the plans at many British sites where some protective actions are initiated on declaration and then thought is given to extending their scope and range if conditions merit it. It is important to realise that, in the UK, the default protective action areas are contained within the DEPZ but not defined by it.

The IAEA have an extended planning distance (EPD), beyond the urgent protective action planning zone, for which arrangements are made to implement further protective actions if monitoring and assessment on the day show that they may reduce stochastic effects if implemented within a day to a week or up to a few weeks following a significant radioactive release. UK outline planning and the gap between the automatic protective action zone and the DEPZ, sort of covers this zone.

Finally the IAEA define an ingestion and commodities planning distance (ICPD) beyond the extended planning distance where plans are in place to protect the food chain and water supply. That this zone is missing in the UK regulation does not mean that the relevant protective actions are not given the attention they deserve. The control of potentially contaminated food and drink is covered in REPPIR-19 (it is part of the operator’s consequence report and mentioned throughout guidance).

The “zones” are a bit arbitrary; are a planning tool and are best reserved for describing the national concept of operations to be applied to a fleet of reactor sites rather than to a particular site. Excellent emergency plans could be written without any use of the terms DEPZ and OPZ. What really matters is that the emergency plan is capable of initiating sensible default protective actions without delay and then rapidly considering the situation and responding to the particular characteristic of the emergency as those characteristics emerge.

I’d prefer to see a process in which the protective actions comes first and the zones second. Sensible plan compontents include:

  • On-site. UK plans tend to be quiet about what happens to the people (possibly several hundred) on the site. I’ve heard reservations about evacuating the site despite the fact that it is probably the only sensible thing to do because it will alarm sheltering residents. Cooping employees up in “mustering stations” i.e. the works canteen does not seem viable beyond a few hours and provides them with little protection.
  • An automatic protective action plan where shelter/exclusion and stable iodine are pre-planned in detail and initiated without discussion on declaration over an area likely to require them in a reasonably foreseeable emergency. (This could be a keyhole shape informed by the wind direction on the day).
  • A deliberative protective action plan that looks at how the protective actions of shelter and stable iodine could be extended further downwind if required and under what circumstances. This plan should detail the monitoring required to support decision making, the decision making process and how the protective actions will be achieved in a timely manner.
  • An agricultural precautionary protective action plan, where thought is given to how far downwind food interventions might be needed as an automatic action and as a deliberated action, what these might be and how they might be achieved. Informing farmers of the implications of this would be part of the public information cycle.
  • An evacuation plan looking at the circumstances under which authorities might want to evacuate areas close to the site (including the potentially hundreds of people on the site) and how it could be done.
  • A communication plan considering how people in the area will be informed of the plans and their parts in them, before any event and how they will be alerted and advised on the day. 

The US concepts of “plume exposure zone” and “ingestion pathway emergency planning zone” are rather more logical than the IAEA ones.

Neither the GSR-7 or REPPIR-19 planning zones definitions are ideal. Since REPPIR-19 has recently been introduced and the planning zones all reviewed there is likely to be little appetite in the UK to make any changes so it will be interesting to see how the ONR cope with this recommendation.

Plant Data

Another observation made by the mission was that “ONR does not have previously agreed format for plant data and information transfer during an emergency” coupled with the suggestion that “ONR should consider establishing pre-defined communication with the operating organizations in terms of plant data and other information during emergencies”.

The big questions here are “what plant data would be useful to ONR?” and “What would they do with it if they had it?”

If ONR were going to analyse plant data in real time and use it to generate advice to the local responders and the national government they would have to greatly extend their expertise in reactor accident management. This would only be a good idea if (a) there is something worth measuring i.e. there are parameters such as temperature, pressure, radiation levels, flow rates that can give the responders better knowledge of what is happening and what is likely to happen next (b) that data is measured and displayed somewhere (c) the ONR know what it means and will definitely be there to interpret it and (d) we don’t really trust the operator to correctly analyse and report the situation.

If ONR just need the data to be better informed spectators then I’d rather not bother.

I remember talking around this subject several times in relation to the rather primitive Magnox reactors. The conclusion was that there were very few parameters that were useful and could be measured and transmitted after a major cooling circuit failure and ignition of a fuel channel fire or two and unless they had happened there wasn’t really a problem. We always thought it would be different with PWRs which have far more instruments and loss of cooling accident sequences with periods where temperatures and pressures could be rising and threatening containment integrity.

RCIS

Another observation was that “The RCIS provides ONR with adequate infrastructure to respond in emergencies and its staff has been increased significantly in recent years. However, ONR does not have an overarching emergency response plan that defines its response objectives, the organizational response structure and functions, how the response actions are coordinated within the RCIS and its external stakeholders, etc. There are RCIS procedures for each position; however, these procedures are not linked together with an overarching document. The new ONR management system, under development, does not currently include a sub-process of ONR EP&R capability maintenance”.

It is a bit surprising that ONR has such a large structure and has recently extended it without actually articulating its objectives. I wonder if everyone has the same view about what it is for.

The mission goes on to observe that “the ONR does not have an overarching emergency response and preparedness plan to coordinate the response functions and maintain response capability within the RCIS. The action plan identified the ONR does not have a formal training and qualification programme for its staff responding to an emergency” and suggests that “The ONR should consider integrating its response arrangements into a response and preparedness plan and formalize training and qualification of emergency response staff”. This could be summarised as “if you are going to do something, understand why you are doing it, work out how you are going to do it and make sure your people know how to do it on the day”. On the face of it, this is sensible advice. 

Having been on both sides of this type of exercise I recognise that only a small fraction of the worth of the exercise is held in the final report. Being on the receiving side and trying to justify your plans and planning process against a polite but sustained challenge from a team of experts who are used to looking at things differently forces you to think deep in a way that the day job seldom does. You learn a lot.

Similarly being on the away team you read reports and think you’ve found gaps but, in discussion, you become to realise that different is not wrong and often where you see gaps you’ve missed the filling in a different component of the plan. They do some things, maybe a lot of things differently to you and many of them they do better than you. Everybody learns, everybody wins.

Keith Pearce, January 2021

What is the case for the nuclear emergency planning community’s snobbishness about improvised respiratory protection for the general public?

In my many years as an emergency planner in the nuclear industry I’ve never heard a real debate about respiratory protection as a public protective action in the event of an accidental atmospheric release of radioactivity. It has always been dismissed because without proper masks and fit testing the protection factors offered are compromised.

In 1981 the IAEA [1] identified that respiratory protection was one way to reduce dose uptake in workers and members of the public. It recognised that high levels of protection require properly designed and fitted devices and realised that these would only be available to those with planned roles in a response. They accepted that if any use is to be made of such measures by the public, the simple equipment and techniques to be employed can only be of a very rudimentary nature.

They provided a quite extensive table of filtration factors for common materials. This included the finding that 16 layers of man’s cotton handkerchiefs provides a geometric mean efficiency of 94.2% against aerosols of 1-5 μm particle size – a protection factor not to be sneezed at. At eight layers the efficiency drops to 88.9%. A single bath towel is worth 73.9%.

The public, they said, “can be advised to use such simple items while proceeding to take shelter, and possibly during sheltering. Similar precautions could be recommended while members of the public were being evacuated from a contaminated area”.

In 2002 the US NCR published a document [2] which suggested that improvised respiratory protection can be used as a secondary protective action that can be used to provide a nontrivial level of additional protection. They also provide a table of protection factors.

In 2007 IAEA stated that [3] “Improvised respiratory protection (e.g. a wet cloth over the mouth and nose) has been shown to be effective but it has not been demonstrated that the public will apply it effectively during an emergency. Improvised respiratory protection should not be assumed to provide adequate protection from an inhalation hazard and therefore its implementation should not be allowed to interfere with evacuation or sheltering”. This does not say that improvised respiratory protection should not be recommended under any circumstances; it just says it should not be used instead of shelter or evacuation.

The latest advice on the protection of the public in the event of a nuclear accident from PHE [4] makes no mention at all of RPE, improvised or otherwise. This publication suggests a dose reduction factor of 0.6 for inhalation dose from shelter in place over the period of a release.

So why have we taken improvised respiratory protection out of our tool box of techniques to reduce public dose? It seems to offer protection factors at least comparable with shelter in place for particulate activity.

We worry about golf courses and caravan parks within our DEPZs where shelter in place is considered likely to be ineffective. Could we at least provide a supply of half decent face masks with the stable iodine tablets we store at these establishments as a secondary protection while thinking about evacuation?

Does the Covid-19 experience that shows that large fractions of the population will wear face masks when advised and has made them far more available to the public change our current attitude?

 

  1. IAEA, Safety Series No. 55, Planning for Off-Site Response to Radiation Accidents in Nuclear Facilities
  2. US NCR, Perspectives on Reactor Safety, NUREG/CR-6042, Rev. 2 SAND 93-0971
  3. IAEA Safety Standards Series No. GS-G-2.1, Arrangements for Preparedness for a Nuclear or Radiological Emergency (2007), https://www-pub.iaea.org/MTCD/Publications/PDF/Pub1265web.pdf
  4. PHE, Public Health Protection in Radiation Emergencies, PHE-CRCE-049, (2019).

DEPZ Determinations under REPPIR-19

I am interested to see what impact on DEPZs we see following the introduction of REPPIR-19 and the bizarre way they are now set. With REPPIR-01 the size and shape of the DEPZ was in the gift of the ONR who had a cumbersome process covering technical, practical and strategic issues (see here). They had detailed discussions with the operator about the site’s safety case and the potential for accident. In this discussion both sides fielded teams of experts, well versed in safety cases and nuclear emergency plans. These discussions could take years.

In REPPIR-19 the safety case still exists and is still discussed at great length between the teams of experts within the operator and ONR organisation. This is a never ending cycle of review and revision.

Under regulation 4 of REPPIR the operator “must make a written evaluation before any work with ionising radiation is carried out for the first time at those premises” (a later clause includes continuing work) and must be “sufficient to identify all hazards arising from the work which have the potential to cause a radiation emergency”. The operator must provide “details of the evaluation” to the ONR. We start to move away from the safety case. Intriguingly this regulation does not require the ONR to bless the work but we can safely assume that if they think it substandard they will require a discussion and a revision. Can’t we?

Under regulation 5 the operator must make an assessment to consider and evaluate a full range of possible consequences of the identified radiation emergencies. This also goes to the ONR but, again, no blessing is mentioned in the regulation.

Regulation 7 requires that the operator produce a consequence report and send it to the local authority. This report is not even a précis of the large body of work that has gone on before. It tells the local authority where the site is, recommends a minimum size for the DEPZ, and discusses which protective actions may be required promptly and how far downwind they should go. This is a very brief document.

Regulation 11 then requires the local authority to consult with a range of organisations and set a DEPZ. What seems to be happening is a local authority officer writes a paper for the council setting out the options (in some cases that might be “this is the proposed DEPZ accept or reject?”). This is discussed at a meeting at which it may not be the only matter to discuss and either rejected or accepted. Did I mention that the local authorities were given a matter of weeks between receiving the consequence reports and having to set the DEPZ by law?

So setting the size of the DEPZ has gone from being in the remit of the national regulator, with teams of experts and able to take their time and apply the same policy uniformly across the UK, to a rushed decision by local authorities who are reassured in the guidance that they don’t need to understand the technical background to the subject. That will work.

I’ll keep track of DEPZ determinations at http://www.katmal.co.uk/reppir2019progress.html .