Transcript Document

SAFETY REPORTS
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
Reg 4
Every operator shall take all measures
necessary to prevent major accidents
and limit their consequences to persons
and the environment
SAFETY REPORTS
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Reg 7(7)
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The operator shall send to the CA a report
containing information which is sufficient
for the purposes specified in Part 1
Schedule 4 and comprising at least the
information specified in part 2 of that
Schedule
Schedule 4-Purpose and Contents
of Safety Report
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Part1-The purposes referred to in Reg7
are as follows:
2. Demonstrating that major accidents
hazards have been identified and that
the necessary measures have been
taken to prevent such accidents and to
limit their consequencesfor persons and
the environment.
Schedule 4 -Part 2
Minimum Information to be included in a
Safety Report
Identification and accidental risk analysis
and prevention methods:
 detailed description of the possible
major accident scenarios
 and their probability -----------
Schedule 4 -Part 2
Minimum Information to be included in
a Safety Report
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Identification and accidental risk
analysis and prevention methods:
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4(b)assessment of the extent and severity
of the consequences of identified major
accidents
(R2P2 p76)
Population
ABC Chem Tank
ALARP in COMAH
For practical purposes:
 All Measures Necessary
(AMN)=SFAIRP=ALARP
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Existing Guidance
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HSE has produced a suite of guidance
documents concerning ALARP. These
are designed to give high level
principles which D/Ds can then use to
promulgate sector specific advice.
The documents are:
Reducing Risk, Protecting People
(R2P2);
Existing Guidance (continued)
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Principles and guidelines to assist HSE in its
judgments that duty-holders have reduced
risk as low as reasonably practicable;
Assessing compliance with the law in
individual cases and the use of good practice;
and
ALARP in Design - Policy and Guidance.
Relationship between R2P2 and the
ALARP Suite
informs*
'ALARP
'R2P2'
Principles and
Guidelines'
informs**
Information
to Stakeholders
HSE's
expectation
e.g. TOR
framework,
primacy of
Good
Practice,
tolerability
criteria
'Good
Practice'
legal commentary
+ policy
Guidance
to Staff
'Design'
D/Ds'
Guidance
HSE's expectation/enforcement policy
* Annex 3 of R2P2 reflects the ALARP guidance
** e.g. the concept of 'hypothetical person' set out in R2P2 is adopted in the ALARP guidance
ALARP Demonstration
"Reducing Risks, Protecting People"
".... suitable controls must be in place to
address all significant hazards .... and
those controls, at a minimum, must
implement authoritative good practice
irrespective of situation-based risk
estimates ...."
"authoritative
"authoritative good
good practice"
practice" =
=
prescriptive
prescriptive legislation,
legislation, ACOPs,
ACOPs,
guidance
guidance produced
produced by
by government.
government.
ALARP Demonstration
"Reducing Risks, Protecting People"
".... both individual risks and societal
concerns .... must be taken into account in
deciding whether a risk is unacceptable,
tolerable or broadly acceptable ...."
"individual risks also give rise to societal
concerns and the latter often play a far
greater role in deciding whether risk is
unacceptable or not."
ALARP Principle
Measures to reduce risk
must be taken until the risk is
broadly acceptable (BA) or
until the cost of further risk
reduction would be grossly
disproportionate (GD) to the
reduction in risk that would
be achieved.
Solicitor`s guidance
"We believe it is right that, in all
cases, the judgment as to
whether measures are grossly
disproportionate should reflect
societal risk, that is to say, large
numbers of people (employees
or the public) being killed at one
go. "
ALARP Diagram
Unacceptable region
Level of risk cannot be justified except in extraordinary circumstances.
___________________________________________________
Tolerable region
If the risks fall in this region then a CASE SPECIFIC ALARP demonstration
is required. The extent of the demonstration should be proportionate
to the level of risk
____________________________________________________
Broadly acceptable region
Level of residual risk is regarded as insignificant and further effort
to reduce risk not likely to be required. ALARP demonstration based upon
adherence to codes, standards and established good practice. These must
be shown to be up to date and relevant to the operations in question.
Case Specific ALARP
demonstration
Operator has to answer the
following fundamental
question:
"What more can I do
to reduce the risks "?
Case Specific ALARP
demonstration
Also:
"Why have I not done
it"?
if the measure appears
reasonable and it cannot be
shown that the cost of the
measure is grossly
disproportionate to the benefit to
be gained, then the Operator is
duty bound to implement that
measure
Proportionate Risk Assessment
The depth of the analysis in the
operators report should be
proportionate to
a) the nature and scale of the
MAHs
b) the risks posed to
neighbouring populations
BLEVE
Risk estimation
Selection of a representative
set of events
Estimation of consequences and frequency
for each event
Ranking & screening (e.g risk matrix, fn
curves)
Risk Matrix (Illustrative)
Likely >10-2
Intolerable
Unlikely
10-4-10-2
Very Unlikely
Intolerable
TIFALARP(Int
olerable if
Fatality >10-3)
TIFALARP(Int
olerable if
Fatality >10-3)
TIFALARP
TIFALARP
Intolerable
Intolerable
Intolerable
Intolerable
Intolerable
Intolerable
TIFALARP/Int
olerable
TIFALARP/Int
olerable
Intolerable
TIFALARP/Br
oadly
Acceptable?
TIFALARP
TIFALARP
50-100 Fatalities
100+ Fatalities
10-6-10-4
Remote
10-6-10-8
Broadly
Acceptable
Single Fatality
Broadly
Acceptable
2-10 Fatalities
11-50 Fatalities
ALARP Demonstration
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But the higher the installation lies on the
societal concerns scale the greater the need
to look for additional measures, over and
above the normal standards.
How to approach?
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1. Identify risk reduction measures.
2. Assess using Lines Of Defence analysis with
cost estimates
3. Possibly, in extreme cases, add a Cost Benefit
Analysis.
Proportionality: Type of ALARP Demo.
Risk reduction
regardless of cost
Intolerable
Relevant Good Practice
Plus
Risk reduction
Measures
Plus
Tolerable if ALARP
Gross
Disproportion
Relevant Good
Practice
Broadly Acceptable
Sensitivity and uncertainty
analysis
Would being more thorough be
worthwhile?
Uncertainties in models, data,
methodology.
Cautious best-estimate basis.
Adopt Precautionary Approach
p89
p89 91R2P2
91R2P2
Purpose of SR is to demonstrate
ANMs (ALARP) from an activity
(`risk from what`)
Four combinations (`risk of what`
and `risk to what`):
1 IR to those on-site
2 IR to those off-site
3 SR to those on-site
4 SR to those off-site
`So what`
If all the risks are BA then
compliance with good practice
demonstrates ALARP
Otherwise the events that
contribute significantly to the
risks need to be identified, risk
reduction options compiled,and
appropriate decision aids used
(eg LOPA for simple cases
CBA for more difficult ones)
If AMNs are in place for each
major accident scenario then
there is nothing more that can be
done and professional judgement
will suffice.
`Explicit` detailed quantification of
risks is not necessary unless the
proportionality is high