The physics of the Chernobyl accident

My latest book, an attempt to explain the Chernobyl accident to people who know a bit about physics but not a lot, placing it between the many accounts that have concentrated on the human story and some very technical reports, is now available on amazon after a professional work over by Art Works who have greatly improved the layout and type setting.

Find it at

What do we know about Covid-19?

Since everybody seems to be writing about Covid-19 I thought I should as well.

COVID-19 is the illness seen in people infected with a new strain of coronavirus not previously seen in humans. On 31st December 2019, Chinese authorities notified the World Health Organisation (WHO) of an outbreak of pneumonia in Wuhan City, which was later classified as a new disease: COVID-19. Based on current evidence, the main symptoms of COVID-19 are a cough, a high temperature and, in severe cases, shortness of breath.

On 30th January 2020, the WHO declared the outbreak of COVID-19 a “Public Health Emergency of International Concern”.

COVID-19 is now classified as an airborne high consequence infectious disease (HCID) in the UK.

Situation reports are available from:

Printed situation reports (worldwide – WHO) are available from:

The world situation can be monitored at

UK Government latest information and advice is available from:

The numbers of confirmed cases in the UK is going to be published daily at 2pm each day on

The table above is from 6/3/20

The Government also maintain a site giving updates on Covid-19: epidemiology, virology and clinical features.

On 30/1/2020 the government raised the UK risk level from low to moderate.


It is not yet clear how this virus will spread and the impact it will have. However, as of 4th March 2020 it is spreading widely across the world and there appears to be an exponentially increasing number of cases in the UK. Business have been advised to plan for 20% absenteeism at the peak.

The government summary of what is known about the virus may be a bit out of date – this is a fast moving event. It does say that “Although evidence is still emerging, information to date indicates human-to-human transmission is occurring. Hence, precautions to prevent human-to-human transmission are appropriate for both suspected and confirmed cases” and “We do not know the routes of transmission of COVID-19; however, other coronaviruses are mainly transmitted by large respiratory droplets and direct or indirect contact with infected secretions. In addition to respiratory secretions, other coronaviruses have been detected in blood, faeces and urine.”

“Fever, cough or chest tightness, and dyspnoea are the main symptoms reported. While most patients have a mild illness, severe cases are also being reported, some of whom require intensive care.”

When you have dyspnea, you might feel:

  • Out of breath,
  • Tightness in your chest
  • Hungry for air (you might hear this called air hunger)
  • Unable to breathe deeply
  • Like you can’t breathe (suffocation)

As of 3 March, a total of 13,911 people have been tested in the UK, of which 13,860 were confirmed negative. 51 were confirmed as positive (up to 85 on the 4th March).

We might expect the number of cases to rise rapidly over a period and then start to drop. The peak intensity and the duration of the disruption is hard to predict. The “social distancing” strategy is intended to reduce the height of the peak but at the expense of increasing the duration. There is a distinct possibility of repeat outbreaks in subsequent years, although these days we can hope that a vaccine will be developed. Each wave can have different inflection rates and different fatality rates. The figure below shows the 3 different waves of illness in the USA during the 1918 flu pandemic.


Figure ref < here>

Government Strategy

( 1st March)

Every government department to have a designated ministerial virus lead to help oversee government response to the global threat of COVID-19

Cross-government ‘war room’ of communications experts and scientists also set up ahead of public information blitz in coming weeks

Further COBRs planned this week, with ministerial COBR meetings upgraded to be held more frequently, if required.

The overall phases of the Government plan to respond to COVID-19 are:

  • Contain: detect early cases, follow up close contacts, and prevent the disease taking hold in this country for as long as is reasonably possible
  • Delay: slow the spread in this country, if it does take hold, lowering the peak impact and pushing it away from the winter season
  • Research: better understand the virus and the actions that will lessen its effect on the UK population; innovate responses including diagnostics, drugs and vaccines; use the evidence to inform the development of the most effective models of care
  • Mitigate: provide the best care possible for people who become ill, support hospitals to maintain essential services and ensure ongoing support for people ill in the community to minimise the overall impact of the disease on society, public services and on the economy.


These phase may have run its course with an increasing number of cases confirmed in the UK. (At this stage care is needed when interpreting the rise in confirmed cases. It may be more representative of the rise in testing rather the rise in cases).


The delay phase of the response will probably be based on public information campaigns urging hygiene, social distancing and recognition of symptoms. The intention is a lower the peak incident rate but probably at the cost of prolonging the course of the epidemic.

The government concern about planning for this stage is that the proposed actions have a social impact (and an economic one).

The company would probably prefer a longer duration, relatively shallow event rather than a shorter, sharper one that compromises site safety by having too many people off at once. At company efforts should focus on delay, at least initially.


For an operational site or company the mitigate stage is about maintaining site safety at all times and remaining fleet of foot to achieve what production is possible.

What happens when you have a suspect carrier on site?

For contacts of a suspected case in the workplace, no restrictions or special control measures are required while laboratory test results for COVID19 are awaited. In particular, there is no need to close the workplace or send other staff home at this point. Most possible cases [currently] turn out to be negative. Therefore, until the outcome of test results is known there is no action that the workplace needs to take. (COVID-19: guidance for employers and businesses).

The Company should consider implementing a policy of “social distancing” and added cleaning.

If it is confirmed that a carrier has been on site the PHE will carry out a risk assessment and give advice to the management (We can imagine that this will only continue to happen if the number of cases remains low).

Self-certification and isolation advice

The self-isolation advice given by NHS-UK is

If there’s a chance you could have coronavirus, you may be asked to stay away from other people (self-isolate).

This means you should:

  • stay at home
  • not go to work, school or public places
  • not use public transport or taxis
  • ask friends, family members or delivery services to do errands for you
  • try to avoid visitors to your home – it’s OK for friends, family or delivery drivers to drop off food

You may need to do this for up to 14 days to help reduce the possible spread of infection.

Home isolation advice can be found at: and for sharing a house with someone in home isolation at

By law, medical evidence is not required for the first 7 days of sickness. After 7 days, it is for the employer to determine what evidence they require, if any, from the employee. (A) Any company should agree and promulgate its policy for sick pay if the virus hits.

Employees may be advised to isolate themselves and not to work in contact with other people by NHS 111 or PHE if they are a carrier of, or have been in contact with, an infectious or contagious disease, such as COVID-19. (A) Again any company needs clear guidance on behaviour and pay under these circumstances.

Office cleaning

Coronavirus symptoms are similar to a flu-like illness and include cough, fever, or shortness of breath. Once symptomatic, all surfaces that the person has come into contact with must be cleaned including:

  • all surfaces and objects which are visibly contaminated with body fluids
  • all potentially contaminated high-contact areas such as toilets, door handles, telephones

Public areas where a symptomatic individual has passed through and spent minimal time in (such as corridors) but which are not visibly contaminated with body fluids do not need to be specially cleaned and disinfected.

If a person becomes ill in a shared space, these should be cleaned using disposable cloths and household detergents, according to current recommended workplace legislation and practice.

Guidance to the cleaners about personnel protective equipment (water proof gloves) and cleaning chemicals to use when cleaning potentially contaminated areas should be clear and transparent. (A) Write and promulgate enhanced cleaning regime for shared areas and for areas that might be infected.

All waste that has been in contact with the individual, including used tissues, and masks if used, should be put in a plastic rubbish bag and tied when full. The plastic bag should then be placed in a second bin bag and tied. It should be put in a safe place and marked for storage until the result is available. If the individual tests negative, this can be put in the normal waste.

Should the individual test positive, you will be instructed what to do with the waste.

How to protect your self

This section based on WHO advice

Wash your hands frequently

Regularly and thoroughly clean your hands with an alcohol-based hand rub or wash them with soap and water.   Why? Washing your hands with soap and water or using alcohol-based hand rub kills viruses that may be on your hands.

How long any respiratory virus survives will depend on a number of factors, for example:

  • what surface the virus is on
  • whether it is exposed to sunlight
  • differences in temperature and humidity
  • exposure to cleaning products

Under most circumstances, the amount of infectious virus on any contaminated surfaces is likely to have decreased significantly by 72 hours.

Once similar viruses are transferred to hands, they survive for very short lengths of time. Regular cleaning of frequently touched hard surfaces and hands will, therefore, help to reduce the risk of infection.

Maintain social distancing

Maintain at least 1 metre (3 feet) distance between yourself and anyone who is coughing or sneezing. Why? When someone coughs or sneezes they spray small liquid droplets from their nose or mouth which may contain virus. If you are too close, you can breathe in the droplets, including the COVID-19 virus if the person coughing has the disease.

Avoid touching eyes, nose and mouth

Why? Hands touch many surfaces and can pick up viruses. Once contaminated, hands can transfer the virus to your eyes, nose or mouth. From there, the virus can enter your body and can make you sick.

Practice respiratory hygiene

Make sure you, and the people around you, follow good respiratory hygiene. This means covering your mouth and nose with your bent elbow or tissue when you cough or sneeze. Then dispose of the used tissue immediately.

Why? Droplets spread virus. By following good respiratory hygiene you protect the people around you from viruses such as cold, flu and COVID-19.

If you have fever, cough and difficulty breathing, seek medical care early

Stay home if you feel unwell. If you have a fever, cough and difficulty breathing, seek medical attention and call in advance. Follow the directions of your local health authority.

Why? National and local authorities will have the most up to date information on the situation in your area. Calling in advance will allow your health care provider to quickly direct you to the right health facility. This will also protect you and help prevent spread of viruses and other infections.

Stay informed and follow advice given by your healthcare provider

Stay informed on the latest developments about COVID-19. Follow advice given by your healthcare provider, your national and local public health authority or your employer on how to protect yourself and others from COVID-19.

Why? National and local authorities will have the most up to date information on whether COVID-19 is spreading in your area. They are best placed to advise on what people in your area should be doing to protect themselves.


Despite a further review of all the available evidence up to 30 November 2012 there is still limited evidence to suggest that use of face masks and/or respirators in health care setting can provide significant protection against infection with influenza when in close contact with infected patients. The effectiveness of masks and respirators is likely to be linked to consistent, correct usage and compliance; this remains a major challenge – both in the context of a formal study and in everyday practice. (

Employees are not recommended to wear facemasks (also known as surgical masks or respirators) to protect against the virus. Facemasks are only recommended to be worn by symptomatic individuals (advised by a healthcare worker) to reduce the risk of transmitting the infection to other people. (COVID-19: guidance for employers and business

Guidelines on soil and vegetable sampling for radiological monitoring. IAEA, Technical Reports Series No. 486

[Report here  IAEA, tech Rep No. 486]

This publication addresses the sampling of soil and vegetation in terrestrial ecosystems, including agricultural, forest and urban environments, contaminated with radionuclides from events such as radiation accidents, radiological incidents and former nuclear activities.

A big issue with surveys of radioactivity in soil and vegetable following a major atmospheric release of radioisotopes is the complexity. We are generally interested in the dose implications of the release to people. There are various pathways to take into account; inhalation dose, cloud dose, ground dose, resuspension dose, direct contamination of foods and uptake into the food chain. You have the situation where a cloud with a range of radionuclides with a range of physical and chemical forms meets a highly complex and heterogeneous system i.e. the real world. How do you decide what to measure? How do you ensure that your measurements are representative? What are your monitoring objectives?

A monitoring programme might be required after a nuclear accident and should be implemented:

  • To help safeguard the environment;
  • To assess hazard, risk and effective response arrangements;
  • To provide public reassurance;
  • To assess the impact on wildlife;
  • To assess the dose to a representative person;
  • To generate data to serve as a reliable database, to establish a baseline, or to substantiate compliance with laws and regulations;
  • To provide an independent check on the monitoring or modelling undertaken;
  • To detect abnormal, fugitive and unauthorized releases;
  • To support legal or regulatory action or to be used in ascertaining compensation and liability in case of spills or accidents;
  • To delineate boundaries for clean areas or to establish priorities and thresholds for the cleanup of contaminated sites;
  • To ascertain the type of treatment or disposal required for cleaning contaminated sites;
  • To understand or assess the long term trends on the behaviour of radionuclides in the environment or the accumulated impact from licensed discharges.

Chapter 2 states that “soil and vegetation can become contaminated when radioactive solids, liquids or vapours are deposited on the surface, mixed with the soil or contaminated from a groundwater source”. It then goes on to discuss some of the factors that affect the fate of deposited radionuclides and the pathways by which people can be exposed to radiation dose (external radiation, skin contamination, inhalation and ingestion).

The IAEA report gives a number of lists of factors that should be considered when a sampling programme is designed. It warns that many sampling programmes fail to achieve their aims because of a failure to take account of the many variables that affect radionuclide movement in the environment.

Warnings such as “the inhomogeneous distribution of contaminants is often the largest contributor to uncertainty in the data and is usually not quantified”; “It is not uncommon for the concentrations of target analytics in soil samples collected within a short distance (e.g. 1 m) to have differences of 50–100%”, “Extreme spatial heterogeneity, such as the presence of ‘hot’ particles (particles of anomalously high activity) in samples can cause large errors in extrapolating the data”; “It is therefore necessary to know about: (i) the source of radioactive contamination; (ii) the physical and chemical characteristics of the radioactive material; and (iii) its depth migration into soils to obtain a representative sample from a field site” are sprinkled through the report.

The report identifies a number of different sampling strategies, judgemental sampling; simple random sampling; two stage sampling; stratified sampling; systematic grid sampling; systematic random sampling; cluster sampling; double sampling; search sampling; transect sampling. They define each of these strategies and have a useful table suggesting which might be appropriate for differ objectives (Table 2.1). This would be a very useful discussion to read prior to starting a major new sampling programme.

There is also a useful discussion about treating the variability of contamination within an area as being composed of three components; the trend across the site, localised variations (hot spots) and random variations. This analysis helps make sense of the distribution of results if applied appropriately.

Section 2.4.1 contains a discussion about the migration of radionuclides downwards into the ground. This depends on the chemical properties of the radionuclide and the soil in question. For example tritium can migrate with soil water and penetrate below root depth very quickly. On the other hand most plutonium is found in the surface few centimetres years after deposition.

An optimal sampling programme achieves the maximum number of objectives, is undertaken in accordance with appropriate quality standards. It is also fundamental that performance criteria (e.g. monitoring and sampling uncertainty, detection limits and confidence levels) are set to meet the objectives, while simultaneously ensuring proportionality and taking account of the urgency of the information required.

In-situ gamma spectroscopy can yield large area data more quickly. These can be undertaken from manned helicopter or fixed wing aircraft, drones at various heights and speeds, vehicles or carried by personnel. Different equipment used in different ways gives a different layer of information. The higher, faster processes cover more area at the expense of detail, good for finding major hot spots. Slower, lower surveys give more idea of local variation. All tend to be variants of a detector (these come with a range of resolutions and efficiencies) coupled to a GPS and a data logger. In practice a layered approach is often optimum.

An approach mentioned by the IAEA is to take a series of measurements, maybe over a number of evenly spaced grid points, and to declare an area as uniformly contaminated if the variation of each measurement from the mean is less than a pre-set value (30% is mentioned). If the variation is greater than this then the area should be subdivided.

The differences in sampling residential, agricultural and forested areas is discussed.

Chapter four discusses the tools and methodologies for sampling in useful detail. Chapter five is about sample preparation. Six quality assurance and seven safety.

Case studies, including in depth reviews of the sampling around Chernobyl and Fukushima, makes up the remainder of the report.

This report is an excellent introduction to environmental sampling. It explains much of the complexity, which many people would underestimate, in an easy to understand manner.

New article in Nuclear Engineering International

I’m pleased to have another article published in Nuclear Engineering International. This one is about EdF’s excellent in-van gamma spectroscopy system which will improve the speed and accuracy of off-site dose estimates if there is ever an off-site release.


Handbook for Regulatory Inspectors of Nuclear Power Plants

Techdoc 1867

Regulatory inspections of nuclear facilities and activities generally consist of a predefined programme of planned inspections and reactive inspections which are both announced and unannounced to ensure that the inspectors obtain a clear understanding of the overall operation of the Nuclear Power Plant. The purpose is to provide independent assurance that the operator is in compliance with regulatory and license requirements and conditions.


This Techdoc is a rather strange accumulation of advice on the inspection process.

GSG-13 identifies four basic methods for obtaining information during an inspection: Monitoring and Direct Observation; Discussions and Interviews; Document Evaluation; and Independent Tests and Measurements. These are expanded on in Section 2.3.2 listing suitable things to inspect in each style and giving hints about how to make the inspection more successful.

Inspections generally should follow a plan – perform – evaluate – report process, which is expanded upon in Section 3, which looks at the phases, and further in Section 4, which looks at how inspections are undertaken. This includes recommending that an inspector be armed with: note book, clipboard, drawings/diagrams; voice recorder; portable computers, tablets; laser pointer; camera; radiation meters; pyrometer/thermal imaging device; and Inspection mirror, providing the site rules allow them.

Section 4.3.1 is an extraordinarily detailed section about some of the components of a nuclear plant (gauges, valves, motors, pumps, pipe supports etc. which seems to be more general plant familiarisation than inspection material. Some nice diagrams are included.

A potentially useful annex gives tables of questions to ask during and after a tour of the plant.

This Techdoc makes an interesting read and could be useful to a reasonably novice inspector as a self-teaching aid and to a more experienced one as a refresher. However, I cannot help thinking that mature national regulators will already have their own material that fits this purpose. For example in the UK the ONR has its extensive set of technical assessment guides (TAGs).

REPPIR 2019 Transition

The REPPIR 2019 regulations come into force on 22nd May 2019.

REPPIR 2019 cover

Any person who had a duty under REPPIR 2001 can continue to use these older regulations until May 2020 when they must be fully compliant with the newer regulations.

So what has to happen within the next 14 or so months?

Regulation 3 (application) is fairly straight forward. The operator must compare their holdings of radioactive material with schedules to determine if the regulations apply to them.

A written “hazard evaluation” is required for sites that pass the regulation 3 test (regulation 4). Preparing this from scratch could be onerous for a complex site but most will already have done a lot of the preparatory work in their safety cases. For licensed sites, in particular, a lot will depend on how the regulators want the work presented. If they are content that the safety case is the written hazard evaluation then little work is required. If they want a special document to cover the regulation then a great deal of work may be required to extract information from the safety case, present it and have the document verified and approved. A document of this nature may have to go to the Safety Committee at least once. A time and resource consuming process.

If the hazard evaluation concludes that there is the potential for a radiation emergency then regulation 5 requires a consequence assessment to “consider and evaluate a full range of possible consequences of the identified radiation emergencies, both on the premises and outside the premises, including the geographical extent of those consequences and any variable factors which have the potential to affect the severity of those consequences”. This could be a lot of work and since it all boils down to “how far out should we be prepared to implement prompt countermeasures” it is largely wasted effort as this result can be achieved with far less work.

Regulation 6 requires the hazard evaluation and consequence assessment be kept under review and updated if anything significant changes. This is no different to the old regulations.

The results of the consequence assessment must be reported to the local authority in the form of a “consequences report” (regulation 7). A meeting between the local authority and the operator should be offered to discuss this report and the operator must comply with any reasonable request for more information.

The local authority then has two months to decide on the extent of the DEPZ and to report it to the operator and regulator. This seems to be a bit ambitious since the regulators, who had more expert resource and a deep understanding of the sites’ safety cases could take several years from receipt of a Hazard Identification and Risk Evaluation document (a required document in REPPIR 2001) to determining a detailed emergency planning zone.

Regulation 9 provides the rules for setting an outline planning zone, a new feature. This is set by a series of rules but only time will tell if these rules result in clear answers.

Regulation 10 requires the operator to produce an emergency plan based on guidance about principles, purpose and content given in schedules. It is likely that operators will have to review their on-sites plans to ensure compliance but not at all clear that this effort will lead to better emergency preparedness. This review will probably fit comfortably within the one year transition period but it will require resources.

Regulation 11 sets the requirement for a local authority off-site plan. Again this will already be in place for most sites but a review against the new guidance would probably be called for. There are a number of changes to dose control and limitation (regulations 18, 19 and 20) that will need to be thought through. Local authorities may find this hard to resource.

A new element of the regulations is the concentration on keeping doses below 100 mSv. There are good reasons to propose this (the IAEA support for the statement that no harm occurs for exposures below 100 mSv, for example) but it may be difficult in some cases, particularly for unlikely severe accidents. The operators may need some time to think through this issue.

The review and testing of plans (regulation 12) is little changed from REPPIR 2001. The only issue might be the disruption to the review and testing programme caused by the introduction of new regulations.

The new regulations demand a lot of consultation, co-operation and agreement (regulations 7, 9, 10, 11, 12, 13, 14, 15, 18, 20, 21, 24). Consultees include other local authorities, category 1 responders, health authorities, public health organisations, regulators, employers, employees. This is well meaning but it takes time and resources and takes the consultees away from their day jobs.

In summary. Within a year of May 22 2019 the operators of nuclear sites are expected to produce a consequence assessment and a consequence report based on their safety cases, the local authority are expected to use this information to determine the extent of planning zones, the operator and local authority are to produce emergency plans compliant with the revised regulations and a significant number of groups are to be consulted, informed or trained.

Writing significant reports in the nuclear industry tends to take a while. They need to be drafted and verified. Reports with the importance of the two related to these regulations would normally go to the site’s nuclear safety committee for review and approval. This is a time consuming process, particularly if the committee wish to see changes and resubmission, which is not an uncommon result particularly for novel reports, as the first of these will be.

The local authority are allowed two months to consider the information provided by the operator and the layout and demographics of their area to decide upon the extent of the planning zones. They will need a process to brief their chief executive and get the conclusion endorsed within this timescale.

Emergency plans may have to be updated if the detailed emergency planning zones have changed (and if they haven’t then pretty much all of the work leading up to this stage has been pointless). Plans will have to be updated to account for the differences in expectations between the 2001 and 2019 regulations, in particular the outline planning zone, the 100 mSv reference level and changes to emergency dose terminology.

It is going to be a busy year chasing tight timescales for some in the local authority and nuclear industry emergency planning world.

Local authority responsibilities under REPPIR 2019

REPPIR 19 (Draft) Title page

Local authorities have responsibilities under the Radiation (Emergency Preparedness and Public Information) Regulations 2001. These regulations are being revised with new regulations, a new code of practice and new guidance all expected within the year.

A draft of REPPIR 2019 and information about the consultation exercise can be found here. More recent drafts of the regulation and guidance are available to some.

Major changes when compared to REPPIR 2001 include a greatly increased role for the local authority in determining the area to be covered by detailed planning – the Detailed Emergency Planning Zone (DEPZ). Previously this has been set by the ONR in consultation with the site operators and local authority but the new Regulation 8 requires the local authority to determine the area on the basis of a consequence report from the operator and their local knowledge. This is potentially an onerous and controversial activity.

Detailed emergency planning zone

8.—(1) The local authority must determine the detailed emergency planning zone on the basis of the operator’s proposal under regulation 7(2) and may extend that area in consideration of –

(a)          local geographic, demographic and practical implementation issues;
(b)          the need to avoid, where practical, the bisection of local communities; and
(c)           the inclusion of vulnerable groups immediately adjacent to the area proposed by the operator.
(2) However, the local authority and operator may agree that, in relation to the premises, other arrangements are in place which sufficiently mitigate the consequences of any radiation emergency, and that no detailed emergency planning zone is necessary.

(3) The local authority must inform the operator and the regulator, within two months of having been sent the consequences report under regulation 7, of the determination made under paragraph (1).

(4) Where the local authority and the operator have agreed that no detailed emergency planning zone is necessary in accordance with paragraph (3), the local authority must inform the regulator as soon as reasonably practicable.(5) On receipt of the local authority’s confirmation of the detailed emergency planning zone, the operator must record the detailed emergency planning zone as finalised.

(6) The local authority may re-determine the detailed emergency planning zone—
     (a) if there is a material change in the local area which necessitates such a change; or
     (b) if the local authority deems it appropriate as a consequence of the operator’s consequences report made after an evaluation in accordance with regulation 6(1) or 6(2)(a).

(7) If the local authority re-determines the detailed emergency planning zone in accordance with paragraph (6), it must inform the operator and regulator as soon as reasonably practicable.

The local authority are not expected to have the deep technical understanding of the site safety case that the operator and regulator have so it is a surprise that they have the duty to set the DEPZ. The operator will provide a Consequences Report which will presumably tell the local authority the distance downwind that they expect ERLs to be exceeded in a number of different faults if events unfold exactly as given in the site’s safety cases and the operator’s dose assessment methodology was spot on with its predictions. Using this table of distances and the accompanying estimates of probability of each fault and combining it with local knowledge of population distribution the local authority can determine where prompt action may avert a useful amount of dose. This is the area where detailed plans are appropriate.

It is stated that “Close attention should be paid to areas where the projected doses approach 100 mSv (Schedule 7, Part 2, 2(d)”. This latter sentence is included because there is an international consensus developing that doses up to 100 mSv in an emergency are unwelcome but unlikely to produce real health effects while doses any higher start to get more worrying (although you can go quite a bit higher before the effects become obvious). It is therefore advised that emergency plans should be designed to keep doses below 100 mSv where reasonably practical. An important part of the setting of the DEPZ would be to identify where, and to whom, a projected dose of 100 mSv or more would result from a given scenario and then consider what could be done to reduce the dose in in the time available. This would set the targets for speed of implementation of any countermeasures.

The local authority are given the following guidance in the draft guidance document:

Para 172 “To determine the boundary of the detailed emergency planning zone, the local authority may adopt an approach as follows:

  1. review the consequences report provided by the operator;
  2. produce proposed detailed emergency planning zone maps based on the consequences report, current planning arrangements and local geographic, demographic and practical implementation issues identified; and
  3. liaise with relevant organisations to identify any issues or improvements to the detailed emergency planning area boundary/boundaries (for example emergency responders, regulators, PHE, operator, adjacent local authorities). Existing local forums and liaison committees already set up to discuss emergency arrangements could be utilised for this purpose.

This paragraph does not shed much light!

ACOP 8(3) gives the local authority another action.

The determination of the detailed emergency planning zone should be reported to the operator and the regulator by the local authority and this should include:

  1. a description of the area;
  2. a map showing the extent of the area; and
  3. a suitable justification for the determination.

The local authority is also being given the power to set specific reference levels where response to a radiation emergency is underway (regulation 20(2)). This is likely to be well outside their comfort zone. Interestingly the Secretary of State can also set reference levels (so no concerns over mixed messages there).

The local authority are being given 2 months to set the DEPZ and a further 6 to complete their plan. This is tight.

ACOP 11(1) xxx An adequate off-site emergency plan should be able to be put into effect without delay when required in accordance with regulation 17(1). To achieve this the local authority should seek assurances from other organisations with a role in the off-site plan that the underpinning capabilities required to implement the plan are in place and readily available. This is an area where the local authority needs to be very careful to work systematically and to keep records. A good quality plan and stakeholder engagement plan is advised.

Charging “16(1)  A local authority may charge an operator a fee for the performance of the local authority’s functions in relation to the off-site emergency plan under regulations 8, 11, 12 and 21”. That is

  • Regulation 8     Detailed emergency planning zones;
  • Regulation 11    Local Authority’s emergency plan;
  • Regulation 12    Reviewing and testing of emergency plans;
  • Regulation 21    Prior information to the public;

Subject to:

Overarching principles

375 The following principles should be followed for all costs charged. Costs should be:
(a)          directly related to, and solely for, the purpose of fulfilling a duty under regulations 8, 11, 12 or 21 of these Regulations,.
(b)          those actually incurred,
(c)           fair, proportionate and commensurate to the duty or risk,
(d)          either for staff time or capital spend, and
(e)          accurately forecasted in advance as far as is reasonably practicable and agreed with the operator.
(f)           Local authorities should make use of existing forums wherever practicable to reduce the costs for duties that require input from other organisations. 
(g)          A detailed breakdown of itemised costs incurred should be provided to the operator promptly following the completion of work. .
(h)          Any unavoidable costs that are not known in advance of work commencing should be an exceptional circumstance and should meet the above principles (a) to (d).

Action: Local authorities should take time to understand Regulation 16 (Charging) and should ensure that the operator has the same understanding and that the cost structure is agreed in advance where possible.

Local authorities have the responsibility to give prior information to members of the public and businesses within the DEPZ. This has been transferred. The duty belonged to the operator in REPPIR 2001. In the previous regulations the operator had to ensure that <people in DEPZ> were supplied with information without their having to request it.  The new regulations require that the local authority ensure that members of the public are made aware of and have access to the relevant information …. We may have to agree the difference between “supply” and “made aware of”. The former can be claimed by putting a leaflet through a door, the latter may not require actual delivery but might require that we force everyone to read about them!

An aspect of REPPIR 2019 that applies to all local authorities is Regulation 22

22.—(1) Every local authority must prepare and keep up to date arrangements to supply, in the event of an emergency in that local authority’s area (however that emergency may arise), information about and advice on the facts of the emergency, of the steps to be taken and, as appropriate, of health protection measures applicable.

The regulations require that these arrangements are able to provide information at “regular intervals in an appropriate manner, without delay, and without their having to request it, to members of the public who are in that local authority’s area and who are actually affected by the emergency”.

The information provided should include factual information about what has happened or is happening and health protection advice such as restrictions on the consumption of food, recommendations to shelter, evacuate or take protective substances and advice on hygiene and decontamination.


The local authority is expected to participate (and presumably record) a number of consultations:

  1. with the operator over the Consequence Report (Regs. 7(5) & 7(6));
  2. on the determination of the DEPZ (Reg. 8);
  3. on the determination of the outline planning zone (maybe) (Reg 9(b));
  4. on the on-site plan (Reg. 10(5c);
  5. on the off-site plan (Reg. 11(5(a-h), 7 & 8);
  6. Generally in respect of duties (Reg. 13);
  7. With other local authorities as necessary (Reg. 14);
  8. Charging (Reg. 16);
  9. With regard to prior information (Reg. 21);
  10. With regard to preparing a system to provide real time information on the day (Reg. 22);

ACTION. I think that local authorities should start keeping detailed records of anything that looks like a consultation as this is the sort of thing that regulators like to audit.

Emergency exposures – It is not clear if there are any circumstances in which a local authority employee would be identified to receive emergency exposures. If there were to be then there will be a lot more detailed work to do (Reg. 18).

Summary: These revised regulations seem to put a lot more responsibility on those local authorities with nuclear sites requiring off-site planning within their area. A lot of this work has been done with regard to REPPIR 2001 and before. However, some of it is new and it is likely that the new regulations will prompt the regulators to take a renewed interest in compliance.

Local authorities should be thinking about how they are going to comply, and how they are going to be seen to comply, with these regulations.


Keith Pearce, February 2019