Project Appraisal Expert evidence at inquiries into ...

0 downloads 0 Views 934KB Size Report
Jul 5, 2012 - Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered office: .... 'learned society' than at a public inquiry.
This article was downloaded by: [University of Southampton Highfield] On: 11 November 2014, At: 08:46 Publisher: Taylor & Francis Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer House, 37-41 Mortimer Street, London W1T 3JH, UK

Project Appraisal Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/tiap18

Expert evidence at inquiries into major hazards a

a

Judith Petts , John Withers & Frank Lees

a

a

Department of Chemical Engineering , University of Technology , Loughborough, Leicestershire , LE11 3TU , England Published online: 05 Jul 2012.

To cite this article: Judith Petts , John Withers & Frank Lees (1986) Expert evidence at inquiries into major hazards, Project Appraisal, 1:1, 3-10, DOI: 10.1080/02688867.1986.9726527 To link to this article: http://dx.doi.org/10.1080/02688867.1986.9726527

PLEASE SCROLL DOWN FOR ARTICLE Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon and should be independently verified with primary sources of information. Taylor and Francis shall not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of the Content. This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. Terms & Conditions of access and use can be found at http:// www.tandfonline.com/page/terms-and-conditions

Project Appraisal, March 1986, Volume 1, Number 1. Published by Beech Tree Publishing, 10 Watford Close, Guildford, Surrey GUI ZEP, England

Public inquiries Expert evidence at inquiries into major hazards Downloaded by [University of Southampton Highfield] at 08:46 11 November 2014

Judith Petts, John Withers and Frank Lees

Problems in the presentation and use of technical information at British planning inquiries include obscurity, incompleteness, inconsistency, and public perceptions. After reviewing these problems, proposals for improvement are made concerning the availability of information at such inquiries, who should participate, the conduct of the meetings (formal and informal), how to structure presentations about safety, the handling of ‘realism’ versus conservatism, and other issues of risk assessment.

Keywords: risk assessment; public inquiries; local planning; major hazards The authors are in the Department of Chemical Engineering at The University of Technology, Loughborough, Leicestershire L E l l 3TU, England. They wish to thank the Science and Engineering Research Council and the Economic and Social Science Research Council for supporting this work.

Project Appraisal March 1986

F

OKMAL Planning or Public Inquiries in Britain, where an official Inspector hears evidence and the public crossexamination of experts, and then reaches a decision, are a comparatively rare event in the chemical processing and similar industries. Site-specific developments are first considered by the local planning authority (LPA), but some decisions are taken by the minister - the Secretary of State - following an inquiry, particularly where the development’s impacts are contentious, or when planning permissions are revoked, or there are appeals against decisions that have been made. The Public Inquiry represents an important opportunity for people to state their opinions in an open forum before an independent Inspector. Since this opportunity is given to the general public as well as to the developer, to the regulatory authority, and to the LPA, i t is important that the process is completely accessible and open and allows a fair hearing to each party, whilst being efficient and timely in its procedures. The system of Public Inquiries has itself been the subject of increasing concern and public debate.’-6 From concern over the delays in the decison-making process, the debate has recently extended to questioning its role where a project is of national importance, and where the issues are technically complex - the ‘big’ Public Inquiry. The recent Sizewell B Inquiry [1983-1985] into plans by the CEGB (Central Electricity Generating Board) to build a pressurized water reactor on the Suffolk coast has highlighted many inadequacies. Fundamental reform of the public inquiry system has been advocated with special reference to investigative processes, the role of parliament, and the funding of legitimate objectors. Whatever may be the need for wholesale reform of the ‘big’ inquiry, there is a strong case for improving procedures which equally affect the smaller inquiry. Such matters as the hearing of evidence by party rather than by issue, inadequate terms of reference, and poorly defined structure, require improvement, especially where the presentation of expert testimony is a key factor. To this end, we first review some recent inquiries into the major hazards associated with specific installations of the chemical process industry, but also include a brief exam-

0268-8867/86/01003-8

US$03.00 0 Beech Tree Publishing 1986

3

Expert evidence at public inquiries

ination of some specific problems thrown up at the Sizewell Inquiry. Proposals for improvement are then suggested and discussed. A fuller discussion of these issues is given by the authors elsewhere. The Inquiries reviewed here are:

Downloaded by [University of Southampton Highfield] at 08:46 11 November 2014

the Mossmorran Inquiry (1977), dealing with proposals by Shell and Esso to build a natural gas liquids plant and ethylene cracker in the Canvey (19808C 1982) Inquiries into United Refineries Ltd permission for a new refinery and the British Gas Operation Of a methane in Essex (south east England; 13-19 the Pheasant Wood Inquiry (1980) into housing development near an 1CI chlorine and phosgene the Sizewe’’ Inquiry (1983-1985)into a PWR power station in eastern E n g l a ~ ~ d . ’ ~ - ~ * Each is briefly outlined in the ‘Four Inquiries’ on the next page.

Key

areas of difficulty

The experience at past Public Inquiries suggests that many of their difficulties with risk assessment can be grouped under one or other of four headings: obscurity, incompleteness, e inconsistency, and 0 public perceptions.

0

0

0bscurity

There may be inherent difficulties in the presentation of the subject matter at a Public Inquiry, or there may be a fundamental difficulty in the subject matter itself. Thus at the Sizewell nuclear plant inquiry, it was difficult to understand the debate on engineering features of pressure vessel construction between rival protagonists whose ideas could only be expressed clearly in engineering drawings. At the Canvey oillgas inquiry, the full risk assessment made by British Gas created difficulties for the Inspector, who felt that their presentation was more akin to that required in a ‘learned society’ than a t a public inquiry. In the Rijnmond Report,29 the many counter-comments occasionally make it difficult, even for experts to obtain a common thread to the argument. (Although the Rijnmond Report is in no way comparable to the documentation required at a Public Inquiry, it still represents the most complete and wide-ranging risk assessment commissioned by a local authority and is available to the general public). Fundamentally difficult matters are typified by the arguments over the frequency of rare events and probabilistic risk analyses at the Sizewell Inquiry. Incompleteness

Information may be incomplete for many reasons. The engineering requirements may not have been worked through at the time of the Inquiry because the project is still at the feasibility phase. There may be undue selectivity in the approach - or even some deliberate omissions. There can be simple failures to identify all the hazards. Thus at the Mossmoman and Sizewell inquiries, much plant-specific data was unavailable because the projects were still in the feasibility phase. Estimates were therefore conceptual and based on generic data. This is likely to be a common situation. Selectivity was demonstrated at Mossmoman, where the

4

objectors were very concerned about hazards at the port which did not seem to have received the attention given to the gas plant itself. Again at Mossmorran, objection was raised to the exclusion of aircraft crashes and the possible ignition of flammable gas leaks by radio transmissions which had not been thought of initially, and which had to be made the subject of a separateinvestigation. Inconsistencies

Some inconsistencies appear at an inquiry simply because of the lack of an agreed structure and methodology for the risk assessment. The use of differing risk criteria can also cause an apparent inconsistency. Differences can also arise due to the differing techniques of mathematical modelling. Examples of differing structures and methodologies appeared at the Pheasant Wood housing/chemic- inquiry where separate assessments were put forward by the developer, the Health and Safety Executive (HSE),-and by the company ICI. HSE did not provide any estimate of individual or societal risk, whilst the other two did (but did not give a full explanation of their methods). The HSE case was based on generic historical data, whilst the ICI case was based on plant-specific data. Examples of the use of differing criteria were demonstrated at Sizewell, where some of the objectors laid stress on relatively high failure rate of pressure vessels obtained from a probabilistic method of risk analysis based on some historical data, whereas the utility (the CEGB) and the local authorities felt that deterministic models based on plantspecific data were more appropriate - giving a frequency some two orders of magnitude lower than that claimed by the objectors. At Canvey, there were wide differences in results obtained from different gas dispersion models. There have also been wide differences in the injury or damage relationships which define the number of people likely to suffer in consequence of a defined effect. Thus the Rijnmond report revealed ten-fold differences in the concentrations of chlorine, as used by various protagonists for the same lethality level. Such differences and uncertainties usually result in judgements being made about the likely margin of error. These judgements may occur at a number of points in the chain of calculations which make up a risk assessment. They may be optimistic or pessimistic. In general, industry is anxious that the risks should not be exaggerated3’ and presses for realistic assessments wherever possible. I t may seek to avoid the use of numeric methods altogether where the confidence bounds are widely ~paced.~l-~~ The HSE, on the other hand, is bound to take a fairly cautious view in the public interest, and to incline towards the use of values such as the lower level of a defined confidence limit which may be regarded as conservative. In risks assessed for the methane terminal at Canvey, the HSE and British Gas sometimes differed by a factor of 100, largely due to a difference between ‘realism’ and ‘conservatism ’.

-

Public perceptions

Whilst a discussion of the public’s perception of risk is beyond the scope of this paper, it has to be recognized that public opposition to an industrial development may be so strong as to influence the character of the presentation and examination of the risk assessments. In Pheasant Wood, there was very little public interest, whereas at Mosmorran and at Canvey the interest was strong and organized.

Project Appraisal March 1986

Expert evidence a t p u blic inquiries

:our inquiries in Great Britain

Downloaded by [University of Southampton Highfield] at 08:46 11 November 2014

blossmorran The main parties to this inquiry were :he LPA (Local Planning Authority), khe developers, the HSE (Health and Safety Executive, an official agency) 3s an independent witness, and a local eesidents' action group opposing the jevelopment. The LPA used Cremer h Warner as their consultants who produced an assessment of the hazards, 3ut the LPA was known generally to 3e in favour of the development. The HSE produced i t s own assessment a t the inquiry, whilst the Action Group also produced technical evidence. No quantitative assessment of the risks was available for discussion. An apparent constraint to a full hazard assessment was the lack of any detailed design data for the proposed plants. (Cremer & Warner's report reviewed various hazards scenarios, and graded their likelihood in qualitative terms such as 'low', 'very low', and 'extremely low'. The HSE's study was entirely qualitative. The lack of quantitative estimates was heavily criticized by the Action Group, who felt that the full nature of the risks could not be discussed properly. However the Action Group's witnesses were able to question the technical assessments of the HSE and of Cremer & Warner's report reviewed various hazard scenarios, and graded approach, particularly of i t s figures for the maximum credible oil spill at Braefoot Bay, and challenged i t s assessment of physical phenomena such as for unconfined vapour cloud explosions. The Group produced risk estimates which indicated that the likelihood of a multiple-fatality accident a t the Aberdour/Dalgety Bay marine terminal might be 100 times greater than had been claimed. The Action Group observed that some potential hazards, such as shipping collisions, appeared to have received comparatively little attention. The issue of possible ignitions by means of high power radio waves was made the subject of a special study by HSE afrer the inquiry. such ignitions arising

Canvey Local public concern over the build up of potentially hazardous industry in the Canvey Island area directly resulted in two public inquiries, - the 1980 Inquiry into the possible revocation of United Refineries Ltd's (URL)

Project Appraisal March 1986

1973 planning permission for a new refinery, and the 1982 Inquiry into possible discontinuance of operations a t the British Gas methane terminal. The 'opposition' a t these inquiries consisted of the local Member of Parliament, the LPA, the Castle Point Refineries Action Group (RAG), and other organized interest groups. The HSE gave independentevidence primarily based on studies specially commissioned from the Safety and Reliability Directorate (SRD) of the UK Atomic Energy Authority. A feature of both inquiries was the availability of fully quantified risk assessments, not only from SRD but also from British Gas. Both the LPA and the RAG employed technical experts to argue their cases. At the 1980 Inquiry, there was much argument over the levels of assessed risks, which were often given quite high values. For example, the calculated fatality risk attributed to the URL extension was made comparable with the national fatality risk a t work. The Inspector considered the risks in some areas unacceptable. In a revised and updated assessment published by HSE/SRD, many of the risks were revised to more acceptable levels, although a t the 1982 Inquiry there were large differences between the two assessments presented by HSE and British Gas. Ultimately, the Inspector decided in favour of British Gas's continued operation a t the terminal, based on HSE's evidence that the plant could be operated safely. Despite the public availability of the SRD findings two years before the 1980 Inquiry, the complexity of the assessment, (which broke much new ground), coupled with the fact that only HSE and the companies had access to actual operating data, meant that the opposition was unable to question adequately the validity of the assessments (even with the aid of academic witnesses). In the adversarial forum, weaknesses in the technical evidence and knowledge of the opposition were readily identified. Despite their willingness to engage in technical debate, they were frequently too emotive and much of their evidence proved to be based on misunderstandings and oversimplified assumptions.

gene storage plant owned by the ICI chemical company arose when the Secretary af State was asked by the HSE to review the proposal after the LPA had indicated that it would grant planning permission. The developer retained Cremer & Warner as consultants, who produced an alternative risk assessment to that of the HSE, whilst ICI, although not directly involved, came forward with a further assessment. The HSE was criticized by the Assessor for the lack of a societal risk estimate in their assessment, and the Inspector recommended that planning permission be granted.

Sizewell This inquiry into the proposal to build a pressurized water reactor for nuclear power generation a t Sizewell began in

January 1983. Proceedings ended two years later after over 300 days of evidence. The Inspector's Reportisexpected in Spring 1986. It i s by any standards a 'big' inquiry. An important feature was that the proposer, the Central Electricity Gen. erating Board (CEGB), had to pay for the inquiry. The potential hazards of the reactor were much debated between technical experts a t the inquiry. (See one witness's views in our next issue.) In addition to the CEGB and LPAs, who were broadly in favour of the scheme, the Nuclear Installations lnspectorate (NII) was called as an independent witness; it i s part of the HSE. Opposition came from the Greater London Council (GLC) and organized pressure groups such as Friends of the Earth. Such groups were assisted by academic witnesses, whilst the GLC retained the firm Technica as consult ants (who produced an alternative risk assessment). T h e NII produced i t s own assessment as did the CEGB, assistec by the National Nuclear Corporatior and the UK Atomic Energy Authority, The LPA used the services of an experl from West Germany. In addition to the help received from a Technical Assessor, the Inspector called an independent expert, Professor T A Kletz, to provide expert evidence on matters of risk assessment. In this article, this inquiry is ol interest not only for the way in which the format of the inquiry developed, Pheasant Wood but also for the evidence given on such This inquiry into proposed 'housing key safety issues as the failure rate 01 development near to chlorine and phos- pressure vessels.

5

Expert evidence at public inquiries The public may regard technical experts as intrinsically biased. Special consideration may be given to the provision of the public examination of expert testimony whenever a strong reaction from the public is likely. The Sizewell inquiry appointed a Counsel to assist in the clarification of issues brought forward by the various parties although, on deeply technical matters, he would invite the Technical Assessor to examine the witnesses directly.

Table 1. Summary of principal proposals 1

Proposals

Downloaded by [University of Southampton Highfield] at 08:46 11 November 2014

The authors’ own proposals are now made for the presentation of expert testimony on hazards at a Public Inquiry. These cover a number of topics, as follows: availability of information, parties to, and personnel at, an inquiry, inquiry arrangements and procedures, formal meetings, the structured safety case, risk criteria, realism and conservatism, and risk assessment issues.

2

3 4

5

Our principle proposals are summarized in Table 1. Availability of information Our main aim in proposals here is to help ensure that at least a minimum of relevant information about safety and related risks is both generated, and made available to other parties. Until recently in Britian, a company proposing to construct a hazardous installation has not been required to present a safety case, but, under newly proposed regulations, such a case will have to be presented to the Health and Safety Executive (HSE) three months before commencement of the activity. I t does not have to be presented to the Local Planning Authority (LPA) or to the public, and is a confidential document. The proposed regulations implement a European Community Directive on Major Accident Hazards and are known as the CIMAH regulation^.^-^^ A much wider range of hazardous installations are subject to notification under the Notification of Installations Handling Hazardous Substances (NIHHS) regulation^,^^ although some installations are surveyable under CIMAH but not notifiable under NIHHS. We propose that a type of safety case should accompany all applications for development of both notifiable (NIHHS) and surveyable (CIMAH) installations. The information which has to be provided for the safety case is specified in the CIMAH regulations and is explained further in the guidance notes to these regulations. The information mostly falls into two categories. The first describes the management structure and procedures for assuring that the process plant is well controlled so far as hazards are concerned. The second describes the hazards and the related risk assessment. The precise nature of the required safety case is not specified and in particular, it is not stated whether the HSE will accept qualitative arguments or demand quantitative estimates. The notes state, “Whilst it may be possible for manufacturers to write a safety case in qualitative terms, HSE may well find it easier to accept conclusions which are supported by quantified arguments.” For large projects, local planning authorities have sometimes requested some form of environmental impact assessment and, within this, some form of safety case. Pro-

6

6 7

10

For a specified planning application a n open safety case should be submitted to the LPA. It should include a risk assessment based upon the structure indicated in Table 2. An outline safety case based on an outline design is adequate although if full design and safety cases have been submitted for a related plant [e.g. for CIMAH] the open safety case should be based on these. The assessment should be realistic rather t h a n conservative. When the LPA consults, it should receive detailed advice on the risks from HSE [and in some cases elsewhere] in addition to the company‘s open safety case. If an Inquiry is held on a notifiable or surveyable installation the submission of written statements by the company and by HSE should be encouraged. An initial formal meeting should be held to decide on the objectives, procedures, timetable, etc, of the Inquiry. These decisions are crucial to its effectiven ess . The role of the HSE at an Inquiry should be to lay down a set of principles by which a judgement may be made. It should state its understanding of the nature of the risk, the safety standards required by the HSWA and enforced by HSE, and give its opinion as to whether the proposed development is likely to conform to HSE‘s requirements. Informal meetings between parties before and during the Inquiry should be encouraged. Formal side meetings should be held during the Inquiry to discuss, but not decide upon, the points at issue. The meetings should be called by the Inspector, who appoints a chairman. Minutes should be taken by a trained secretary. Members of the public should be able to attend at the invitation of the Inspector and the minutes and other documents tabled should be given the status of official Inquiry papers. Experts called by objectors should be encouraged to avail themselves of the side meetings to clarify issues and avoid misunderstandings and errors. Technical assessors should, as now, be appointed to help the Inspector where appropriate and the appointment of a Counsel to the Inquiry should be considered for large, technically complex projects. The advantages of adversarial examination of expert testimony outweigh the disadvantages and should be used in the main meetings of the Inquiry.

blems have tended to arise with such studies for three main reasons: there has been considerable variety in the scope and structure of the studies; the degree of completeness has varied widely, and the LPA may have had little experience in evaluating such matters. The execution of a project is a phased process and, at the stage when outline planning permission for a new installation is requested, the design isusually only an outline appropriate to the feasibility phase. Nevertheless it is considered that such an outline plan should be sufficient for the purposes of a risk assessment. The information required concerns the main process and storage units, together wtih terminal facilities, inventories, and operating conditions. This would normally be sufficient to allow the identification of potential releases of hazardous materials in the risk assessment. This type of information was used in the Can-

Project Appraisal March 1986

Downloaded by [University of Southampton Highfield] at 08:46 11 November 2014

Expert evidence at public inquiries vey studies even though the plants were actually operating presumably because it was much more readily available within budgeted time and cost. Whilst such a risk assessment based wholly on generic data will be appropriate when seeking outline (first step) planning permission, it seems probable that any public inquiry would demand a fuller assessment. There will normally be an appreciable period between a planning application and an inquiry, and this could give the company time to update its safety case as appropriate. It is desirable that the structure of such a safety case should conform to the structure of all such cases, whether open or confidential, previously submitted or not. Any case prepared for the purposes of a public inquiry also must be necessarily an open (and not confidential) safety case. Whilst it will be limited to the effects from the company’s installation, it may be that the boundaries are wider than those of the initial, outline case. The dialogue between industry and the LPA during the planning application is important, and the presentation of open safety c v e s in a uniform style will allow LPAs to become familiar with the subject. I t is therefore proposed that there should be an accepted structure for risk assessments, whether the safety case is open or not, and this structure is discussed below (and summarized in Table 2). An inquiry may now start its work without the benefit of a safety case from a company. The proposals just made would ensure that, for any notifiable or surveyable installation an open safety case would be available. However, even if this were to be so, it would remain true that the case would be presented by an interested party. Well before any inquiry, an LPA may wish to commision an independent report from a consultant, in addition to seeking advice from the HSE. The standard structure proposed for safety cases will assist the LPA to provide meaningful terms of reference to such a consultant. The HSE should provide a sufficiently full and quantified estimate for the Inspector to use as the main independent testimony against which he can assess the evidence of all other parties. If such an HSE safety case is available, together with a company safety case, and an additional assessment provided through the LPA, it should be unnecessary for the inquiry to seek further supplementary sources of evidence during the proceedings. (This is not to limit the right of other parties to commission such studies.) Twenty eight days before the inquiry, the LPA is required to produce a written statement. I t is only the LPA which has this obligation. The lack of any requirement for the applicant to provide a written statement prior to the inquiry has been much criticized and it is proposed that both the company and the HSE should provide such statements, so as to assist all concerned to formulate their evidence. Parties and personnel The LPA will always be a party to a planning inquiry. There is no general requirement that staff from other government

We propose there be an agreed structure for risk assessments, and that the evidence for a proposed project’s safety be made available to the public in all relevant cases Project Appraisal March 1986

bodies (such as the HSE) should appear in person. However, it appears highly desirable that staff from both the company and the HSE should appear when requested, so that they may be questioned by all concerned on their written statements. At the present, when a government department has expressed in writing the view that the application should not be granted (or granted only with conditions), and the LPA have included this view in their written statement, then the applicant is entitled to have a representative of that department called by the LPA as a witness. The parties will often be represented by legally-trained counsel at the inquiry. An innovation at the Sizewell B Inquiry has been the appointment of a Counsel to the Inquiry. This appointment seems to have greatly helped the Inspector and other parties to clarify several issues. His investigatory role in the advenarial process is potentially invaluable and, although the inquiry may be prolonged on this account, such an appointment should be considered for all technically complex projects. The Secretary of State may appoint an Assessor with safety expertize to assist the Inspector. He advises the Inspector and may examine witnesses, but is not examined himself. He may provide a written report for the Inspector, who may quote it verbatim in his report. The function of the Technical Assessor appears satisfactory and should not be changed. The part played by the HSE in a public inquiry needs to be seen in the context of its wider and on-going role in the control of hazards. If this role is to be safeguarded, it is desirable that as far as possible it should be seen as an advisor rather than as a protagonist. The HSE should at the outset of each inquiry be invited to state its role, the legislation under which it operates, its powers under the legislation, and the limits of such powers. I t should define the set of principles by which it judges the nature of the risk and the relevant safety criteria required by the Health and Safety at Work Act, as enforced by the HSE. The HSE may also indicate its expectations of the ability of the developer to meet these standards, but should leave it to the inquiry t o balance these expectations with those of others, and with other relevant factors. The recommendations of the Inspector may then take the form of approval, subject to the more detailed and sitespecific requirements of the HSE at a later date. These requirements may well involve a management audit as well as a technical inspection. I t is undesirable that the HSE should have to instigate an Inquiry, as inthe case of Pheasant Wood. This undermines both the role of the MSE and the position of the LPAMany experts are called by objectors. These experts should be encouraged to play their part in the formal and informal meetings discussed below. In this way, issues will be clarified and many difficulties of the past will be avoided. In addition, independent wimesses have been called by Inspectors, as a t Sizewell. There appear to be n o problems in such cases. Arrangements and procedures Large inquiries usually have a formal preliminary meeting presided over by the Inspector. At this meeting a detailed set of objectives, procedures and timetable are developed from the terms set by the Secretary of State. Such a meeting is vital for all inquiries on large, technically complex projects.

7

Expert evidence at public inquiries

Downloaded by [University of Southampton Highfield] at 08:46 11 November 2014

Small, formal meetings should occur to help participants in the appraisal process to clarify which points are (or are not) agreed. These meetings should be by invitation only The normal procedure in a public inquiry is to hear evidence by party rather than by issue, with the project’s proposer having the final right to reply. This results in the safety evidence being interspersed with evidence on other topics, and not taken in its own logical order. In big inquiries, however, hearing may be by issue (as at the Sizewell Inquiry). In general, hearing by issue suits the large organizations, who have little difficulty in making experts available on each issue as it arises. However, it may create problems for the smaller bodies with limited funds, who may prefer to give their evidence in a single presentation even though it may cover several issues. Thus this administrative matter has relevance to the comparative effectiveness of the larger or smaller parties. Formal meetings Informal meetings between parties should be encouraged in order to help settle the points that are agreed, as well as clarify the points in dispute. There has been some criticism of the adversarial nature of a cross examination in a public inquiry as it may serve to emphasize extreme positions rather than reveal the truth. Although it may be true that technical experts may be loathe to participate in such a p r ~ c e d u r e , ~in’ the eyes of the public it remains the best safeguard against concealment, and is therefore felt to reflect the true purpose of a public inquiry . Despite the undoubted difficulties, we believe that the advantages of the adversarial process outweigh the disadvantages. I t should therefore be retained. However, we propose that, during the inquiry, there should be formal nonadversarial ‘side’ meetings between all the parties concerned, which are directed towards a clarification of the technical issues rather than their resolution. Such meetings should be instigated by the Inspector, who would appoint a chairman. Closed meetings are liable to excite suspicion, but open meetings can inhibit a free exchange since it is difficult to encourage an informal atmosphere that is not unstructured. Thus we propose that attendance will by invitation from the Inspector, but that invitations shall not be withheld unreasonably. I t is important that a record be kept of such meetings but verbatim transcripts are unlikely to be helpful. i t is therefore proposed that a trained secretary should draw up minutes of the meetings, which must be approved by the parties concerned. They should be treated as formal inquiry documents, open for public examination and available as a basis for cross-examination during the main inquiry procedures. Such meetings need not lengthen the inquiry. Quite apart from making possible a technical debate in a more satisfactory environment than is possible under normal inquiry procedures, such meetings will act as a preliminary filter, thus saving time and effort in the main inquiry forum. They will also provide a well identified and problem-specific set

8

of papers invaluable as a technical record. Previous inquiries have been unsatisfactory in this regard. Structured safety case The main purpose of the proposal for a structured safety case (emphasis on the ‘structured’) is to improve the clarity of the presentation of the risk assessment issues, and to avoid the surprise emergence of an issue which may have been neglected. (We have already proposed that an open safety case should be available at the start of an Inquiry. Table 2 outlines a structure for a complete assessment, including individual and societal risks. In some cases the assessment may be terminated at an intermediate point, such as after the estimation of frequency and magnitude of any releases. The risk assessment is based on the assumption that there are adequate management systems to, enforce control of potential hazards. Such an assumption may beverified by methods of hazard identification such as ‘hazop’38 studies, although this is probably unnecessary for outline planning permission - but not later. Risk criteria I t is recommended that a phased approach be taken in the risk assessment, with separate considerations being given to on- and off-site casualties. Most risk assessments evaluate the chances of death, since this appears to be a simple and unambiguous criterion. There are, of course, several classes of risk where the public may perceive a fate worse than death, and it is often remarked that no assessment of risk is meaningful unless benefits are considered alongside. In the case of major hazards, emergency plans need to be made and rehearsed, and, in addition to the possible number

Table 2. Structure for risk assessment reports 1

System definition Definition of system and system boundaries (eg inclusive of transport) Description of installation (inclusive of processes, inventories, vessels) Release patterns Statement of causes of release, including causes not considered (eg aircraft crashes) Estimate of frequency and magnitude of releases (data sources and methods to be referenced) Emergency scenarios These will comprise chains of events from emission through dispersion to damage to property and people Estimate of frequencies and chances down the chain (data sources and models to be referenced) Statement of damage and injury relationships (models and population data to be referenced) Presentation of results Individual risks on-site and off-site, eg using plot plans, risk transects, and contours Societal risks on-site and off-site, eg giving accumulated annual fatality rates a t various locations, and frequency number [f/n] curves Statement of criteria against which risks may be judged Relevant comment leg sensitivity analysis)

Project Appraisal March 1986

Downloaded by [University of Southampton Highfield] at 08:46 11 November 2014

Expert evidence at public inquiries

of fatalities, an estimate of the number of injuries will be required. This may be derived from the estimate of fatalities. Individual risk is first calculated, since it does not require any knowledge of the population distribution and can be compared directly with a number of actuarial figures and, for example, the ‘acceptable’ criterion provided by the UK Royal Society Study Individual risk-contours provide a helpful initial screen whereby a perceived problem may be further investigated. Societal risk is probably the most important issue in the public mind, related to its fear of catastrophic events. Criteria for the evaluation of societal risk are still under debate.40 The evaluation of the results of the risk assessment using a set of risk criteria involves value judgements, and so (inevitably) disagreements. I t is helpful however to put the results into a context, so as to clarify issues. In Table 2, it is suggested that the results be compared with the corresponding criteria for individual and societal risk. The debate on risk criteria will continue but it does not now seem hopeless to envisage the growth of an understanding about the use of risk criteria as an aid to decision making. I t is uncertain how far the HSE will reveal their thinking on the use of critiera although, at the Sizewell inquiry, the Nuclear Installations Inspectorate eventually made their position clear. Criteria proposed by industry may be thought biased, but constitute an important input to the debate (since they derive from practitioners). There is scope for inputs from independent sources, but it should be recognized that the subject is still under development and this must be understood when deciding what weight to place upon the results. Realism and conservatism A degree of caution is appropriate when dealing with a prospective major hazard. Nevertheless it is proposed that, in the first instance, a risk assessment should aim to be realistic rather than conservative. Information should be provided on the sensitivity of the result to uncertainties in the assumptions. The estimate can then be viewed with an appropriate degree of conservatism. How far a risk assessment should go depends upon the nature and level of the risks and the public perceptions. I t seems unlikely however that a risk assessment presented to a public inquiry would be considered complete without estimates of individual and societal risks. Differences in expert estimates both of the frequency and the consequences of accidents are inevitable, but may be made more understandable by a more explicit recognition of the different types of data which may be used. For example, when estimating the frequency of a very rare event, historical data or engineering principles may be used. History is liable to give a higher figure than engineering (but both can contribute to a decision). Differences over consequence estimates may derive from the damage relationships employed, or from the population distribution that has been assumed. Any differences may be clearer when their nature is properly explained, and the sensitivity of the final outcome to the uncertainty is shown. (There are signs that both in frequency and in consequence, the differences are becoming less: figures for the frequency of pressure vessel failure show a converging trend, while the range of hazard distances given by the main gas dispersion models has narrowed appreciably.) Project Appraisal March 1986

Risk assessment issues Whilst on-site risks may be calculated with confidence and related to any number of accident statistics (and perhaps to tangible rewards), off-site risks, though certainly lower, are much more difficult to ascertain, and are usually involuntary. I t is sometimes suggested that risk analysts should a b stain from making an evaluanon of their work. But a familiarity with the data is part of the evaluation requirement, and there is every reason for utilizing the risk analyst’s expertize. However, advice must be understood for what it is, and the expert should not appear to be arrogating to himself matters which are not his exclusive province. Among the assumptions made in any risk assessment are those about the quality of management. I t may be argued that the assessment should be based on a favourable view of the managerial skills. This ought not to be an argument for making the assessment itself less conservative, but may be an argument for making a proper allowance for the managerial factor. The public probably recognize that an evaluation of risks involves choosing between things which are not strictly comparable, under conditions of uncertainty. This is a task which industrial management face every day - as indeed do members of the public. Technical experts should bear in mind that particular risks produce particular fears which may not be open to direct comparison, and there remains much room for a greater understanding of the risk perception of particular hazards.41 Risk assessment is not the only form of reassurance which can be given to the public. Another is a clear perception of a strong safety policy, executed under the control of effective and experienced management. Once however, a plant has fallen into public disrepute, there will be no avail, not even from a hazard warning structure.4z I t is to be hoped that a company’s modifications of its proposals as a result of a public inquiry should not be seen as a sign of previous neglect. Decisions on particular features are often finely balanced, and the recognition of other views should be seen as a sign of responsibility rather than weakness. I t may be that the public are not prepared to play the experts’ game, and reject the whole concept of risk assessment. They may simply say that any such risks are too great. However, at Mossmorran, particularly, there were signs that, if the assessment process could be trusted and if the estimates were sufficiently low, then there would be little concern. But installations need to be seen to be safe in practice as well as in theory, and it is unlikely that any written statement can give the reassurance that comes from a satisfactory relationship developed in close proximity over many years. Conclusion The problems of expert testimony a t British Public Inquiries into process industry developments or installations have been described and proposals made to mitigate them.

The proposers of hazardous projects need to see any changes they make following a public inquiry as a reflection of their strength and sense and not of their previous incompetence 9

Expert evidence at public inquiries

The aim of the proposals, summarized in Table 1 , is to improve the existing system rather than to replace it. They are addressed particularly to the safety case and the risk assessment, summarized in Table 2. They are intended to provide more information to the inquiry and, in particular, a safety case, at least in outline; to make the safety case more uniform in structure and to clarify many of the areas of difficulty. We hope that the disagreements between experts will then become more understandable so as to secure a more informed public, and hence more effective public participation.

18.

19. 20. 21. 22.

References

1.

Downloaded by [University of Southampton Highfield] at 08:46 11 November 2014

2.

3. 4. 5. 6.

7. 8.

9. 10. 11. 12.

13.

14. 15.

16.

17.

10

P Sieghart, editor, The Big Public Inquiry (Outer Circle Policy Unit, London, 1979). B Wynne, "Windscale: a case history in the political art of muddling through", Prog. in Resource Management & Environmental Planning, 1980,2, page 165. R Kemp, T O'Riordan and M Purdue, "Investigation as legitimacy: the maturing of the big public inquiry", Geoforum, 1984,15, page 477. A Barker, "Planning Inquiries: a role for Parliament", Royal Society of A r t J., 5337,1984, page 619. Roval Town Planning Institute. The Public and Planning: Means to &tter Participation, (London, RTPI, 1982). Department of the Environment, Draft Code of Practice on Inquiry Procedures, Consultative Docu. ment, (London, 1984). Scottish Development Department, Report of the Public Inquiry into the Shell/Esso Mossmorran/ Braefoot Bay Proposals (Edinburgh, 1978). Cremer and Warner, The Hazard and Environmental Impact o f the Proposed Shell NGL Plant and Esso Ethylene Plant at Mossmorran and Export Facilities at Braefoot Bay (London, 1977). Health and Safety Executive, Statement of Evidence to the Mossmorran-Braefoot Bay Public Inquiry, 1977. J R Sutcliffe, "Shipping risks at Braefoot Bay", Science and Public Policy, October 1980, page 356. S Macgill, 'The United Kingdom case study: a summary', In H Kunreuther and J Linnerooth (editors) Risk Analysis Decision Processes (Springer, 1983). Health and Safety Executive, An Assessment of the Hazard from Radio Frequency Ignition at the Shell/ Esso Sites at Braefoot Bay, Fife (London, HM Stationery Office, 1978). Health and Safety Executive, Canvey: An lnvestigation of Potential Hazards from Operations in the Canvey Island/Thurrock Area (London, HM Stationery Office, 1978). J I Petts, The Control o f Major Hazards: The Canvey inquiries (Department of Chemical Engineering, Loughborough University, Loughborough, 1985). Sir R Ward, Reopened Exploratory Inquiry into the Desirability of Taking Action to Revoke the Planning Permission Granted to United Refineries Ltd on the 28 March 1973 for the Construction o f an Oil Refinery on Canvey Island, Essex June-July 1980 (Department of Environment El15215178911.1980). Health and Safety Executive, CanveyaSecond Report. A Review of Potential Hazards in the Canvey Island/ Thurrock Area Three Years after Publication of the Canvey Report (London, HM Stationery Office, 1981). A de Piro, Exploratory Inquiry into the Desirability of Initiating Proceedings for Discontinuance of the

23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34.

35. 36. 37. 38. 39. 40. 41.

42.

Use of the British Gas Methane Terminal on Canvey Island 25th January-25th May 1982 (Department of Environment E l 15212178918,1982). British Gas Corporation, Assessment of Risk to the Public. Proof of Evidence to the Exploratory Inquiry into the British Gas Methane Terminal, Canvey Island, 1982. Health and Safety Executive, (Canvey 1982 Evidence). S Reese, Inspector's Report on the Pheasant Wood Inquiry (Department of Environment PNW 50631 219116,1981 1. Health and Safety Executive, Preinquiry Statement on the Pheasant Wood Inquiry, 1981. Cremer and Warner, Assessment of the Proposed Pheasant Wood Development Scheme in Relation to the Hazards and Risks Associated with the ICl Thornton Site. Proofs of Evidence of G J Lewis and R Sylvester-Evans, 1981. Imperial Chemical Industries Ltd, Pheasant Wood Inquiry. Proofs of Evidence by R C Paul, J S Smith and N C Harris, 1981. CEG BINNC, PreConstruction Safety Report and Reference Design Sizewell 'B'PWR (April 1982). Sizewell 'B' Inquiry Proceedings Days 202, 216, 229, 243,320,321, 328-340. Sizewell 'B' Inquiry NllISI92, NllISI83, TAKlPI1. Sizewell 'B' Inquiry GLC/P/G+Adds, CEGB P16, CEGBl511066. Sizewell 'B' Inquiry LPA/P/4+Adds, CEGBl.51933. Rijnmond Public Authority (1982), Risk Analysis of Six Potentially Hazardous Industrial Objects in the Rijnmond Area, A Pilot Study (Dordrecht: Reidel). B H Harvey (Chairman), Third Report of theAdvisory Committee on Major Hazards (London, HM Stationery Office, 1984). CONCAWE, Methodologies for Hazard Analysis and Risk Assessment in the Petroleum Refining and Storage Industry, Report 10182 (The Hague, 1982). International Study Group on Risk Assessment, "Quantified Risk analysis in the Process Industries", Chemical Engineering 1982, page 385. International Study Group on Risk Assessment, Risk Analysis in the Process Industries (Rugby, Institution of Chemical Engineers, 1985). European Community, 'Council Directive of 24 June 1982 on the Major-Accident Hazards of Certain Industrial Activities', Official Journal of the European Communities, 1982, No L 23011.5.2.82. Health and Safety Executive, Guide to the Control of Major Accident Hazards Regulations, 1984, (London, HM Stationery Office). Notification of Installations Handling Hazardous Substances Regulations, 1982 (London, HM Stationery Office). J F Davidson "On Public Inquiries", Chemical Engineering, 404, 1983 page 31. T A Kletz, "Hazop and Hazan"Noteson the Identification and Assessment of Hazards (Institute of Chemical Engineers, Rugby 1983). Royal Society Study Group, Risk Assessment, London 1983. D 0 Hagon, "Use of Frequency ConsequenceCurves", Chem. Eng. Res. Des, 62, 1984 pages 381-6. T R Lee, "The public perception of risk and the question of irrationality", in Sir F Warner and D H Slater (editors) The Assessment and Perception of Risk (London, Royal Society, 1981). F P Lees, 'The Hazard warning structure of major hazards', Transactions of the Institute of Chemical Engineers, 1982, 60, page 221.

Project Appraisal March 1986