Engineering Justification Paper
RIIO-ED2 Programme Level Report
Ref No L&S EJP 7 – Enhancements due to fire risk
assessments
Date 30 June 2021
Engineering Justification Paper
Enhancements due to fire risk assessments | Ref No.: L&S EJP 7
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30 June 2021
Table of Contents
1
Summary Table
4
2
Introduction
5
3
Background Information
6
4
Optioneering
8
4.1
Option 1 – Do nothing
9
4.2
Option 2 – On-site FRA at all substation plus remedial work where identified
9
4.3
Option 3 – Mix of Desktop and On-site FRA dependent on risk-level
9
4.4
Option 4 - Carry out a desktop FRA of all substations
10
5
Analysis and Cost
11
6
Deliverability and Risk
13
7
Conclusion
14
Appendix A - ENA Engineering Recommendation S39
15
Table of Tables
Table 1-1 Investment Summary
4
Table 3-1 Fire Risk assessment matrix
6
Table 3-2 Substation types
6
Table 4-1 Summary of Options
8
Table 5-1 Substation inspection categories
11
Table 5-2 Fire Risk Assessment enhancement cost delivery profile
12
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Enhancements due to fire risk assessments | Ref No.: L&S EJP 7
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Acronyms and Abbreviations
ALARP
As Low As Reasonably Practicable
CP
Code of Practice
EJP
Engineering Justification Paper
ENA
Energy Networks Association
ENA ER
Electricity Networks Association Engineering Recommendation
ENWL
Electricity North West Limited
FRA
Fire Risk Assessment
G&P
Grid and Primary
HV
High Voltage
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Summary Table
Table 1-1 below provides a high-level summary of the key information relevant to this Engineering
Justification Paper (EJP) related to the enhancements ensuing from a structured fire assessment
process.
Table 1-1 Investment Summary
Enhancements due to fire risk assessments
Name of Scheme/Programme
Enhancements due to fire risk assessments
Primary Investment Driver
Safety
Scheme reference/mechanism or category
Multiple projects
Output references/type
Fire Protection - Substations
Cost
£7.8m
Delivery Year
RIIO-ED2
Reporting Table
CV14 – Legal & Safety
Outputs included in RIIO ED1 Business Plan
Yes
Spend apportionment
ED1
ED2
ED3+
£0.6m
£4.4m
£2.8m
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Introduction
Under the Regulatory Reform (Fire Safety) Order 20051, we have a responsibility to carry out general
fire safety precautions for all of our premises to ensure safety of our employees and other personnel
on site. Section 8-1 states:
“Duty to take general fire precautions
8.—(1) The responsible person must—
(a) take such general fire precautions as will ensure, so far as is reasonably practicable, the
safety of any of his employees; and
(b) in relation to relevant persons who are not his employees, take such general fire
precautions as may reasonably be required in the circumstances of the case to ensure that the
premises are safe.”
In 2017, to assist electricity companies in discharging these duties as they apply to their substations,
the Energy Networks Association (ENA) published Engineering Recommendation S39, ‘General fire
precautions in substations at 132kV and below and in enclosed cableways.’ A copy of this document
is provided in Appendix A.
ENA ER S39 includes the following guidance:
“Whilst all substations will fall under the Order, it is probable that a generic assessment can
be used for substations of similar design (such as modern unit-type distribution substations)
located in similar environments. It is likely that most grid and primary substation will need to
be individually assessed.”
During RIIO-ED1 we have established our Fire Risk Assessment process and carried out 750
assessments at indoor substation sites. This has led to development of policy and an assessment of
the work needed to bring the fire risk to as low as reasonably practicable. As a result of this work we
have been able to identify the type of assessment required for each site and the expected volume of
remediation work resulting from these assessments.
We have taken the guidance in ENA ER S39 and published our own Code of Practice (CP) 357, Fire Risk
Assessments for Operational Sites, which sets out our approach to fire risk assessments. This
document is currently under review to ensure it is current and describes the most effective approach
to maintain safety from fire at substations.
We have approximately 18,000 ground mounted distribution (HV) substations and around 560 Grid
and Primary (132kV and 33kV) sites.
To carry out FRAs in the most efficient manner, whilst ensuring that fire risk is properly identified and
mitigated, a combination of generic desktop assessments and on-site risk assessments is used.
As this programme of work is to ensure the safety of our staff and customers, we are planning to
complete all the remedial work identified from the FRAs by the end of RIIO-ED2. Investment in this
area in future years will be as required to maintain safety.
1
https://www.legislation.gov.uk/uksi/2005/1541/contents/made
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Background Information
The complexity of our Grid and Primary substations requires an individual on-site survey and risk
assessment with regards to fire precautions.
Likewise, all distribution substations in third party buildings and those within larger buildings also
require individual on-site surveys related to fire risk assessments.
For distribution substations in outdoor compounds and in smaller standalone buildings, a desktop risk
assessment approach has been adopted. There are a large number of these sites (over 75% of our
total substation population), which are expected to pose a limited fire risk. If the results of the desk
top FRA indicate a Moderate (or higher) risk, as defined in Table 3-1 below, then these sites will then
be subject to an on-site FRA. Substations assessed as Negligible or Tolerable risk will not have an onsite FRA.
Table 3-1 Fire Risk assessment matrix
Likelihood of Fire
Low
Medium
High
Potential consequences of fire
Low
Medium
High
Negligible risk
Tolerable risk
Moderate risk
Tolerable risk
Moderate risk
Substantial risk
Moderate risk
Substantial risk
Intolerable risk
This desktop FRA is based on the substation size, its construction material (for indoor buildings), its
location in relation to other properties, evidence of materials being stored around the substation and
evidence of interference or vandalism.
The numbers and types of substations in our network is given in Table 3-2 along with the survey
category required.
Table 3-2 Substation types
FRA category
Substation type
Number
Desktop
Outdoor distribution
6,002
Desktop
Small indoor distribution
8,344
On-site
Large indoor distribution
1,182
On-site
Buried
On-site
In a third-party building
On-site
Grid & Primary
50
2,435
561
Where the result of a desktop FRA is that a substation is Moderate risk, an on-site assessment will be
carried out to validate the result of the FRA and identify enhancement works required. On-site
assessments look at items such as potential sources of fire, measures to contain fire and risk to people
should a fire occur.
Currently, no sites have been identified as higher than Moderate risk from desktop FRAs.
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The desktop FRAs in Table 3-2 above have resulted in 1,258 substations being identified as Moderate
risk and in need of an on-site FRA.
The full breakdown of on-site FRAs required is shown in Table 5-1 below.
Additional questions have been added to the routine substation inspection scripts to identify fire risk
factors at all substations which will allow validation of the desktop FRAs or will identify where an onsite FRA is required.
The on-site and desk-top FRAs identify the fire risk posed by the substation and the on-site FRAs also
identify any remedial works to mitigate the identified risks thus ensuring we bring the risk to an ALARP
(As Low As Reasonably Practical) condition.
Experience of enhancements ensuing from FRAs is that these works include installation of fire resistant
doors in place of timber doors, sealing of wall penetrations (i.e. where cables or services go through
walls) and improvement to the fire protection of ceilings.
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Optioneering
A summary of options are given in Table 4-1 with further detail in sections 4.1 to 4.4. Options 2 to 4
differ in their approach to the FRA plan (desk-top, on-site, or a planned mix of both). All these three
options include the requirements for remedial work if identified by the FRA.
As this is a safety programme to bring all substations to an ALARP level of fire risk, we are planning to
complete all remedial work identified from FRAs by the end of RIIO-ED2.
Table 4-1 Summary of Options
Option
Description
Advantages
Disadvantages
1.
Do nothing.
Nil cost.
We will not have discharged
our duty under the Regulatory
Reform (Fire Safety) Order
2005 to carry out general fire
safety precautions for all our
premises.
2.
On-site FRA at all substations. Enables a site-specific risk
assessment to be completed
for each substation with
Complete remedial work
appropriate remedial works
identified.
identified and implemented
for each as appropriate.
Higher cost than a targeted
survey and takes longer to
complete.
Mix of Desk-top and on-site
assessment dependent on
Risk level.
Does not enable a detailed
individual site assessment to
be made at those sites subject
to desktop assessment.
Much of the effort would be
spent at sites which could be
adequately assessed by a
Achieves compliance with the desktop survey as being lower
regulations.
risk.
3.
Complete remedial work
identified.
Focuses effort and resources
to those substations more
likely to be higher risk. Less
expensive than on-site fire
risk assessments at all
substations and more costeffective.
Achieves compliance with the
regulations.
4.
Desk-top FRA at all sites.
Lower cost.
Complete remedial work
identified.
Achieves a level of
compliance with the
regulations.
The complexity some of our
installations means that they
are non-standard and sitespecific conditions requiring
remediation may not be
identified.
Compliance
with
the
regulation may not occur.
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4.1 Option 1 – Do nothing
Failure to carry out FRAs at our substations and implement any remedial work identified will leave us
in breach of the Regulatory Reform (Fire Safety) Order 2005.
For this reason, this option is discounted.
4.2 Option 2 – On-site FRA at all substation plus remedial work where identified
This option enables a site-specific FRA to be carried out at each substation. Following this, any
remedial work identified would be carried out. However, analysis of substation location and the
nature of their construction shows that over 75% are likely to be lower risk.
Carrying out site-specific inspections at all sites will divert resources from sites likely to be higher risk
and make it more difficult to carry out assessments and remediation in a timely manner.
This approach will be higher cost than a targeted approach supported by desktop assessments, whilst
not offering a material improvement in fire safety.
For these reasons, this option is discounted.
4.3 Option 3 – Mix of Desktop and On-site FRA dependent on risk-level
Option 3 provides for a desktop FRA of substations that can be identified as being likely to be lower
risk and focussing of on-site assessments to those sites more likely to be higher risk. It includes the
requirements to complete any remedial work identified.
By identifying those substations most likely to be at lower risk we can focus our resources on higher
risk sites. Detailed on-site FRAs will identify remedial work required to ensure that the fire risk is as
low as reasonably practicable and improve safety for our staff and customers.
Where desktop FRAs indicate that the fire risk is too high, we will target those sites for an on-site
assessment.
Additional questions in our routine substation inspection scripts will allow us to continually validate
the results of the desktop FRA and identify any changes in and around the substation which cause its
FRA to change.
This option will allow us to carry out on-site FRAs at the highest risk sites and to implement remedial
measures identified in order to bring the fire risk as low as reasonably practicable.
This is our preferred option.
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4.4 Option 4 - Carry out a desktop FRA of all substations
In this option, we would carry out all FRAs as a desktop exercise. Whilst a lot of our sites are of a
standard design, this does not apply to higher voltage substations, larger distribution substations and
sites located either adjacent to or within third party buildings. In these cases, their complexity and
potential use of non-standard materials can only be identified after an on-site inspection and FRA.
Adoption of a theoretical total desktop study has the potential to miss key aspects of a building’s
construction. This would produce a risk assessment that is inadequate and hence would not comply
with the regulations. This option has been discounted.
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Analysis and Cost
Section 4 (Optioneering) recommended Option 3 which proposed performing on-site surveys at Grid
and Primary substations and those located in third party/larger buildings. Desktop FRAs would be
used at outdoor distribution sites or those in standalone buildings to assess the fire risk and indicate
whether there would be an additional need for an on-site survey.
Analysis of 750 sites where fire risk assessments have been carried out since the start of RIIO-ED1 has
shown that 345 (46%) require work to reduce their fire risk. The average cost of this work is £2,927
per substation.
The differences in shape, size and construction of sites, means that we have estimated our RIIO-ED2
programme based on the unit cost from the work completed and planned in RIIO-ED1. Not all sites
identified for remediation work will be completed during RIIO-ED1 and have therefore been added to
the ED2 submission.
The data from these substation surveys has been used to identify the scale and cost of work required
in RIIO-ED2 to bring the risk of injury from fire at substations to as low as reasonably practicable.
The total numbers of substations that required on-site FRA are shown in Table 5-1 below. This is the
total volume of survey work which we began in RIIO-ED1.
Table 5-1 Substation inspection categories
On-site inspections required – substation category
Number
Moderate risk (from desktop assessment)
1,258
Distribution Complex - Large indoor > 40m2
1,182
Buried
50
Grid & Primary Substations
561
Part of a larger building
2,435
Total
5,486
We have used the percentage of the number of sites requiring remediation work compared to the
total number of sites assessed during RIIO-ED1 to be an indication of the number of sites requiring
remediation work in RIIO-ED2.
We therefore forecast that 46 %, or 2,524 sites, require enhancements after an FRA. We are carrying
out enhancements at 208 of these sites during RIIO-ED1 leaving 2,316 sites to address during RIIOED2 & ED3.
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A proposed cost and delivery profile is shown in Table 5-2.
Table 5-2 Fire Risk Assessment enhancement cost delivery profile
Year
RIIO-ED1 2023/24
Cost (£m)
0.6
Totals (£m)
ED1: 0.6
Number of sites to
remediate
208
Total number of sites
(ED1/ED2)
ED1: 208
0.9
2024/25
2025/26
0.9
0.9
2026/27
2027/28
ED3
0.9
0.9
2.8
298
298
825
ED2: 4.4
299
298
298
ED2: 1,491
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Deliverability and Risk
In common with all civil works carried out at our substations, this enhancement work will be delivered
by our network partners who will resource as required to accommodate this programme.
We have commenced this programme during RIIO-ED1 by carrying out enhancements at 208 sites.
This will leave 2,316 sites requiring enhancement at an estimated cost of £6.77m (see Table 5-2
above).
In a small number of the locations where we have a substation in a third-party building, the necessary
enhancements may involve the co-operation of a building owner to give us approval to do work or to
carry out works for which they are responsible.
As we would be reliant on a third party for approval or completion of these works, there is a risk that
they will not be carried out as promptly as desired. Where this occurs, we will deal with each on a
case by case basis with due regard to the level of fire risk and the legal position regarding our
substation location.
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Conclusion
We have a responsibility under the Regulatory Reform (Fire Safety) Order 2005 to carry out general
fire safety precautions for all our premises.
By carrying out desktop FRAs of substations most likely to be at lower risk and undertaking on-site
FRAs at higher risk sites we can target our resources for assessment where they will give best benefit.
The outcome of the FRAs will indicate the remediation required to meet regulatory standards.
Providing the programme of assessment, and the ensuing delivery of enhancements identified from
these FRAs, will enable us to comply with legislation and improve safety for our staff and customers
in the most cost-effective manner.
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Appendix A - ENA Engineering Recommendation S39
ENA_ER_S39_Issue
1_(2017).pdf
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