IAEA-TECDOC-1867

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. http://www.legislation.gov.uk/uksi/2019/703/contents/made

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

REPPIR19
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.

Consultation

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

National Radon Strategy

UK National Radon Action Plan, PHE-CRCE-043 https://www.gov.uk/government/publications/uk-national-radon-action-plan

`The abstract to this document claims that “This report presents in a single document, the elements that make up the national radon strategy and the national radon action plan. It fulfils relevant requirements in the 2013 European Union Basic Safety Standards Directive on protection against ionising radiation (EURATOM, 2013).” I think that this statement admits the thought that occurred to me as I read the document for the first time; although labelled as the UK National Radon Action Plan it is not really a plan or a strategy, instead it is a comprehensive description of the work being undertaken in the UK to understand the extent of exposure to Radon, to identify where action should be taken to reduce Radon dose, and to take such steps and monitor their effectiveness.

The section labelled “UK radon strategy” talks about the UK strategy in the third person. It is not a strategy itself but describes a strategy that is off-stage. Where the document states that the UK strategy meets the requirements of the BSS it is really making the credible claim that the UK is already doing what it would have decided to do had it started with a blank sheet of paper and written a strategy in line with the guidance. Essentially the UK had a comprehensive Radon programme before the need was fully articulated in the BSS.

Radon appears in the BSS in a number of places (Article 54 Radon in the workplace, Article 74 Indoor exposure to Radon, Article 103 Radon Action Plan). The BSS requires that there is a national plan to address the long- term risks from radon exposure recognising that the combination of smoking and high radon exposure presents a substantially higher individual lung cancer risk than either factor individually and that smoking amplifies the risk from radon exposure at the population level.

The Ionising Radiation (Basic Safety Standards) (Miscellaneous Provisions) Regulations 2018 which came into force on 8th May 2018 require the Secretary of State to set a reference level for public exposure to radon. The reference level for the annual average radon activity concentration in air must not exceed 300 becquerel per cubic metre (regulation 8) in line with BSS Article 74. The BSS calls for a “basis for the establishment of reference levels”. The basis of the UK limits is not clear to me but there is probably a justification somewhere.

Further regulation is found in the Health and Safety at Work etc Act of 1974 and the Management of Health and Safety at Work Regulations 1999.

The SoS is also required to publish information about the hazards of indoor radiation, its measurement and ways of reducing it (Regulation 9). This is satisfied, at least in part, by the website at https://www.ukradon.org/.

There must be a national plan address long term health risks from radon ingress to dwellings, workplaces and buildings with public access (Regulation 10). This must be updated at intervals of no more than five years.

Annex 18 of the EU BSS gives a list of 14 things to consider when setting up a national radon plan. The use of this list is mandated by the 2018 regulations.  While I don’t think that the UK is missing anything important with the current approach it is not entirely obvious where each of these topics are covered.

Public Health England have a group focused on the radon issue and they provide leadership within the UK. This document was written by the PHE group along with several other government departments covering the UK and the devolved administrations.

The UK has maps are that identify radon Affected Areas, which are defined as where at least 1% of homes are expected to be above the radon Action Level (200 Bq m-3). These can be found at https://www.ukradon.org/. This shows that my home in Gloucestershire has a “maximum radon potential of less than 1% (in the clear) but with the surrounding area going up to 3 – 5%. Since these values are “indicative” I’m maybe not entirely in the clear.  This clearly shows that the need for an “approach, data and criteria for the delineation of areas” is satisfied. It is less clear that a risk assessment has been used to systematically identify the types of buildings that should be surveyed although the UK has a long standing survey programme.

The Forward plan for action on radon states that established UK infrastructure and provisions will be “maintained and supported” but not who will do this and who they will be answerable to which you may expect to find in a strategy. The New topics for consideration” explicitly mentions the annex of the EU BSS and picks up some of the missing elements and promises that they will be given attention and places actions, but not a time frame, on Public Health England.

Maybe next time the PHE will publish a document that looks more like a strategy. In the meantime keep up the good work.

References

EURATOM (2013). Council Directive 2013/59/EURATOM of 5 December 2013 laying down basic safety standards for protection against the dangers arising from exposure to ionising radiation, Official Journal of the European Union L13/1.

Ionising Radiation (Basic Safety Standards) (Miscellaneous Provisions) Regulations 2018 (which came into force on 8th May 2018)

Two new pieces of advice for local authority emergency planners

Local authorities’ preparedness for civil emergencies: A good practice guide for Chief Executives And A councillor’s guide to civil emergencies

The Ministry of Housing, Communities & Local Government has reissued advice to local authorities on preparedness for civil emergencies (Local authorities’ preparedness for civil emergencies: A good practice guide for Chief Executives, November 2018). This document, which is not intended to be prescriptive, lists 10 aspects it would expect to see in a well prepared authority.

In the introduction Jake Berry MP states that the nature of emergencies facing us continue to increase in variety and complexity “terror attacks in London and Manchester, the use of nerve agent in Salisbury and the devastating fire at Grenfell Tower have tested the resolve of our communities and reminded us all of the importance of local authority leadership in times of crisis”.

The section entitled “are you ready” asks nine questions about:

  • the ability of residents to contact the authority including out of hours and on bank holidays;
  • the authority’s ability to communicate risks and to warn and inform people in the area, including tourists and other visitors, before, during and after an emergency;
  • the ability of senior staff and elected members to manage in an emergency, including managing the authority’s role and as a senior officer within the strategic response and recovery mechanisms;
  • the testing of plans to ensure that they address local risk and resilience standards and describe how to maintain essential services, ensure business continuity and contain agreements with other local authorities for support in a crisis;
  • the resilience of supply chains;
  • the role of the authority within the LRF and the accuracy of the role description in multi-agency plans and the ability to deliver;
  • resource plans for no notice and sustained emergencies, including over holiday periods;
  • a knowledge of the authority’s strengths and weaknesses and where support and further resource can be obtained;
  • the ability to assess the full impact of an emergency on community needs.

The report discusses the role of the local authority in civil resilience in terms of the CCA, in which the local authority is a category 1 responder.

Importantly the regulations or guidance require that the local authority “to ensure that they can continue to exercise their functions in the event of an emergency. The duty relates to all functions, not just emergency response functions”. This appears to include the ability of an authority to provide support to any population within countermeasure zones during a nuclear emergency. “Plans should be clear about what operational support the local authority will put in place for different emergencies, and how this can be activated in and out of business hours” …. “Plans must be clear about how this support will be activated and managed. This support could include on the ground community alerting, for example, door knocking, checking on vulnerable residents, operating rest centres and providing on-going welfare support for people directly affected by emergencies”.

To achieve this all business critical functions should have robust business contingency plans for the services that the authority delivers and those that are contracted out.

An example that is pertinent to nuclear authorities is “consider building ‘all-risk resilience’ into contracts (for example, how to ensure domiciliary care is delivered during petrol shortages or severe disruption to transport networks)”. Reinforcing this is the statement that “Local authorities are expected to manage the humanitarian aspects during emergencies. This requires staff at all levels to be effectively trained to deal sensitively with victims and survivors, including their friends and family. Training and exercising reserves and volunteers builds a further level of resilience in the event of concurrent or long duration incidents”.

An example of communicating with the public given is that of Calderdale Council which utilised social media during floods in December 2015. It is claimed that the council reached over 420,000 people on Facebook and received over 1 million impressions on Twitter.

On the matter of community leadership the document states that “The public, media and politicians will also look to the council to provide information and clarity on what has happened, what is still happening and what will happen next”.

The importance of training and exercising is stressed. It builds “confidence and competence to enable robust delivery of the local authority role whether it is delivered in response or recovery”.

A list of useful documents is given at the end of the document.

This is a document that should be read by the local authority manager responsible for emergency planning and by the Chief Executive of the authority fairly regularly. It might be a useful one to have on the desk when performing periodic readiness or accountability reviews. At a mere 27 pages it makes a welcome change from some of the “door stop” guidance documents that sap the will to live.

A related document, A councillor’s guide to civil emergencies” has also been updated recently (November 2018). The forward mentions that the last version was issued in 2016 but reports that a lot has happened since then with terrorist attacks, tower fires and nerve agent attacks within the UK.

This document introduces some core terms including the definition of a civil emergency, the difference between a rising tide and a no-notice event, categories of responders and levels of response.

A number of case studies are discussed.

The overview section outlines the responsibilities of councils and individual councillors and, later, the role of leaders, portfolio holders and Ward councillors. These headings are then revisited in sections devoted to “preparedness and resilience”, “response”, and “recovery”.

Appendices give suggested questions for leaders/portfolio holders (Appendix 2) and scrutiny committees (Appendix 3) to ask.

This document is a good read and a useful resource for councils and councillors.

IAEA Lessons learned from the deferred dismantling of nuclear facilities

https://www-pub.iaea.org/books/iaeabooks/12194/Lessons-Learned-from-the-Deferred-Dismantling-of-Nuclear-Facilities

This document discusses the requirements to manage sites entering the Care and Maintenance stage of decommissioning (sometimes called deferred dismantling in IAEA documents and SAFESTOR in the USA) where most of the quick wins in terms of cleaning out components have been achieved and the sites waits for several decades for radiological decay to reduce dose rates to more manageable levels before final dismantling of the reactor core and buildings in completed. It is estimated that about 50% of the nuclear facilities that have been shut down are in safe store and that learning from these sites is increasing. This document was written to allow the benefits of that experience to be shared. It was drafted and reviewed by consultants managed by the IAEA

The document discusses the length of time a site may wait before dismantling based on the half-lives of the isotopes giving most of the dose on the one hand and the deterioration of the structures and containment on the other. It concludes that 15 – 20 years is often a sensible duration provided that there is a suitable waste repository for the final waste arisings.

Section 2 of the document talks about the facilities that are required in safestore, the options to repurpose existing buildings during safestore and the removal of unnecessary buildings. It provides reports of experiences and photographs. Several of the examples are based on the experience of Magnox, which as an ex-employee, pleases me.

Section 3 is about the preparations for safestore. This includes the recording of the hazard inventory and a hazard management plan (remove it or make it safe for the duration of safe store), clean up and deplanting, decontamination, drainage and protection.

In a section on firefighting it states that the risk of fire can be reduced by removing as much of the combustible material and as many ignition sources as practical in the preparations for Care and Maintenance phase. However, it states that a firefighting plan is still required and should be developed and agreed with the local fire fighters and the regulators.

Where external firefighters are the first responders familiarisation training, fire plans, exercising and testing are recommended. For unmanned sites there is a need for automatic alarms that reach the firefighters and the site’s management and access arrangements for the local firefighters. These firefighters must have the appropriate security training and classification to enter the site unescorted.

Security measures are required to keep people off the site to avoid vandalism, damage and theft and also to reduce damage by vermin.

The continuing need for environmental monitoring of radionuclides is discussed in Section 6.6. This is likely to be a regulatory requirement but at a lower level that when the site was operating. It is suggested that it would be sensible to taper off monitoring after a period of about five years by which time a workable baseline understanding of the site would have been achieved. There is a warning that new release pathways may be revealed in time.

The interesting bit of this document for me is the section on emergency planning.

The document (Section 7.5) states that “emergency planning and preparedness (EPP) is necessary for a safe enclosure as it contains large amounts of radioactive materials due to structures, systems or components activation and contamination in various parts of the facility”.

As the risks of the facility reduce the operator should review and rewrite emergency plans to ensure that they remain fit for purpose. Off-site measuring equipment can be reduced but is still required and must be maintained. I assume this is referring to off-site radiation detection. In my experience this is sensibly reduced to perimeter monitoring equipment because of the small releases feasible from such structures do not give a sufficient signal very far downwind.

The document admits that it might be difficult to get the local authorities to agree on the need to maintain and test emergency plans for a site in safestore and suggest that the need to be able to deal with protestors and intruders might be one selling point.

There are sections on the management and regulation of sites, the costing of decommissioning activities (including an introduction to a system called the International Structure for Decommissioning Costing).

Section 12 and several of the annexes of the report give outlines and experiences of decommissioning projects around the world including Magnox’s lead and learn process which has been used to ensure that learning is shared between the different sites and that the process becomes more effective and cheaper with each subsequent site.

This publication does not represent in-depth guidance on care and maintenance of decommissioning nuclear sites. It provides a high level review of the aims of care and maintenance and some of the key considerations. Several examples are discussed. As such it makes interesting reading and may be useful as an introduction to the field for those in operating facilities that are coming to the end of their design life.

Nuclear Emergency Response for Local Authorities: An Introduction by Keith I Pearce

I’m very pleased to announce that my second book has now been published on Amazon. I’ve enjoyed writing this one. It attempts to explain nuclear emergency response to those who know little or nothing about the industry. It is based on the knowledge I’ve gained working on safety cases, dose assessment, emergency preparedness and emergency response. I hope it will help local authority and emergency services personnel in particular but be interesting to a slightly wider readership.

Buy it here:  https://www.amazon.co.uk/dp/1916465803

Visit the publishers website (http://www.katwab.co.uk/)

 

 

The Chilca Incident – industrial over-exposure

The Chilca Incident

The IAEA have published a very detailed review of this event and the learning to be gained from it. https://www-pub.iaea.org/books/IAEABooks/11095/The-Radiological-Accident-i

n-Chilca

A serious radiological accident occurred in Peru around midnight on 11 January 2012 during non-destructive testing in the district of Chilca, in the Cañete Province of Lima. An iridium-192 source in a radiography camera being used to test pipeline joints became stuck inside the guide tube, resulting in three workers being overexposed to ionizing radiation.

Pipes were being welded together and a radiography camera was being used to determine the quality of the welds. The equipment used consisted of a 192Ir source inside a shield (see picture). When an exposure is required a remote winding mechanism is used to move the source from inside the shield, along a tube and into collimator – this produces a beam of gamma rays that are used to make the measurement.

The process involves attaching the collimator and guide tube to one side of the pipe being tested and an unexposed film to the other side of the pipe, then retreating, winding

Device used to store and deploy radiation source

the source out, making the exposure and then winding the source in and repeating. The blackening of the film shows where gamma rays have been less well attenuated and can highlight defects in the weld or pipe wall. The team of three took 97 exposures during a night shift. Finishing at 02:20 on 12 January 2012.

The company provided the workers with a kit that included a set of tools and equipment for operational and personal safety. However, the two assistants, Co-worker 1 and Co-worker 2, left their personal dosimeters in the transportation vehicle; thus, Worker 1 was the only worker wearing a personal dosimeter. None of the workers used alarming dosimeters or direct reading dosimeters. They did not adequately test that the source was returning to the shield at the end of each exposure.

At the end of the shift, when the equipment was being dismantled, it was discovered that the source had not returned to its housing.

At 02.30 worker 1 was sick and he continued to be sick for the next few hours. In the course of the night co-worker1 experienced fatigue and co-worker 2 dizziness.

On investigation it was found that some of the films were overexposed.

On 15 January 2012 erythema (redness of the skin or mucous membranes, caused by hyperemia (increased blood flow) in superficial capillaries which occurs with any skin injury, infection, or inflammation and is a symptom of radiation burning) appeared on the left hand index finger of Worker 1. The company then realized that the workers had been overexposed to radiation.

The Peruvian Institute of Nuclear Energy (IPEN) was alerted and responded by recommending hospitalisation of the three workers. A formal request for assistance (the first of three as the situation developed) was sent from IPEN to the IAEA on 20 January 2012 under the Convention on Assistance in the Case of a Nuclear Accident or Radiological Emergency (the Assistance Convention) for dose reconstruction and medical advice. International support helped to understand the medical conditions of the exposed workers and determine their treatment, to understand the doses received and to consider further actions.

The prodromal symptoms of the three were carefully recorded and they were subjected to close examination and observation. The three patients were classified in accordance with the Medical Treatment Protocols for Radiation Accident Victims (METREPOL) system. This considers neurovascular, haematological, cutaneous and gastrointestinal issues and rates each person on a scale of 1 (minimum severity) to 4 (maximum severity) for each. Consideration of the symptoms displayed, the time to onset and their severity allows the doctors to estimate the dose and dose distribution received by a patient and this allows them to predict the course of their illness and to determine the most appropriate treatment.

Worker 1 was the most severely exposed to radiation during the accident. He received a significantly heterogeneous whole body dose of 1.8 Gy (with 75% of the body having received a dose in the range of 4 Gy), as well as doses ranging from 20 to 50 Gy to the extremities of both hands. He was subject to a programme of care and investigation in Peru, Chile and in France. He received reconstructive surgery and cell therapy (mesenchymal stem cells (MSCs) or MSC injections) but still had to have parts of his hand amputated on day 101 after the event.

It was concluded that the work had been badly managed. The trained radiological protection officer was not present, the equipment had been assembled by an untrained person, no attempt had been made to confirm the correct retraction of the source, there were no alarming dosimeters and two of the team were not wearing the supplied dosimeters. This shows poor application of rules and guidance and a poor safety culture.

An observation was that “significant time (6 d) was taken to recognize the radiological nature of the accident, despite the availability of substantial evidence and clinical manifestations. Consequently, as has happened in many other radiological accidents, valuable time was lost before the workers were given appropriate medical evaluation and treatment.” It is suggested that doctors should be trained to suspect and to identify the effects of radiation when patients present with the symptoms of acute radiation syndrome or their case history suggests it is possible.

It was observed that there were problems associated with the analysis of samples and with the sending samples by airline as they demanded confirmation that they were not dangerous. There were also delays with treatment, particularly treatment abroad, on cost grounds, the workers lacking insurance.

The important message here is that these accidents happen and are continuing to happen. Could it happen in the UK? We would like to think not but it only takes a few mistakes with this type of equipment to result in over-exposure. Would it be detected more quickly? We would like to think so. There is at least a suggestion that the workers involved were not open with their initial reports as they feared blame for failing to work to procedures more than they feared the consequences of overexposure and delayed treatment.

This could happen in any county in the UK. It is worth being aware of that and considering how the local authority would react to an event in their area.