Memorandum submited by Mr Phillip Bratby
DRAFT NATIONAL POLICY STATEMENT (NPS) FOR
NUCLEAR POWER GENERATION (EN-6)
EXECUTIVE SUMMARY
The current regime for the licensing of nuclear
power stations is briefly described. The procedure has been successfully
developed over many years. The applicant submits a safety case
to the Nuclear Installations Inspectorate (NII), which grants
a licence if it is satisfied that the risks to the general public
and workers are as low as reasonably practicable. EN-6 is
proposing the addition of a dangerous prescriptive element to
the licensing regime. This interference in the licensing process
must be resisted and the relevant sections of EN-6 should
be deleted.
The effect of a new fleet of nuclear power stations
upon the needs to store higher level waste is minor and it is
expected that technological developments will be such that the
safe long term storage of the wastes will be available when needed.
INTRODUCTION
1. My name is Phillip Bratby. I have a first
class honours degree in physics from the Imperial College of Science
and Technology (London University) and a doctorate in physics
from Sheffield University. I am a semi-retired energy consultant,
being the sole director of my own consultancy company. I worked
in the military and commercial nuclear power industry for over
33 years. My main areas of expertise are in the safety and
operation of pressurised water reactors. I was involved in the
Sizewell B project from its inception, including the Sizewell
B public inquiry, the design, construction, commissioning and
first 10 years of operation.
PART 1 NUCLEAR
LICENSING
2. The license to operate a nuclear power
plant in the UK requires the applicant (licensee) to submit a
safety case to the regulator (Nuclear Installations Inspectorate
(NII)) which decides, based on the safety case and use of the
NII Safety Assessment Principles (SAPS[6])
and the guidance provided by the Technical Assessment Guides (TAGs[7]),
whether to grant a nuclear site licence. The NII does not prescribe
the contents of the safety case or the data or methods on which
it should be based. The onus is upon the applicant to produce
a safety case that the regulator finds acceptable in that the
overall risk to workers and members of the public is broadly acceptable
or tolerable and is as low as reasonably practicable (ALARP[8]).
The tolerable level of risk (TOR) to the public and workers from
nuclear power stations was developed by the Health and Safety
Executive (HSE) following recommendations made at the Sizewell
B Public Inquiry.[9]
The NII SAPS have been developed over many years and contain best
practices to ensure safe operation of nuclear power stations.
3. The NII SAPS state: NIIs inspectors
use these Safety Assessment Principles (SAPs), together with the
supporting Technical Assessment Guides (TAGs), to guide regulatory
decision making in the nuclear permissioning process. Underpinning
such decisions is the legal requirement on nuclear site licensees
to reduce risks so far as is reasonably practicable, and the use
of these SAPs should be seen in that context.
4. In addition, the NII states:[10]
1.13 The licence conditions provide the basis for regulation
by HSE. They do not relieve the licensee of the responsibility
for safety. They are non-prescriptive and set goals that the licensee
is responsible for meeting, amongst other things by applying detailed
safety standards and safe procedures for the facility.
5. Thus it can clearly be seen that the
UK licensing process is non-prescriptive. The adoption of a prescriptive
licensing regime in the USA was one of the factors relevant to
the Three Mile Island Accident. The imposition of prescriptive
licensing rules by the US Nuclear Regulatory Commission (NRC)
led the vendors to concentrate on the large loss of coolant accident
(LOCA) to the virtual exclusion of the higher risk small LOCA.
The UK regulatory regime enables the applicant to make his own
safety case, which, through the use of a probabilistic safety
analysis (PSA), ensures that all envisaged hazards and risks are
included in the safety case so that the risks are made as low
as reasonably practicable (the ALARP principle).
6. However, section 3.7 of EN-6 "Climate
change adaptation" appears to be imposing prescriptive licensing
rules on applicants. EN-6 states:
3.7.6 In consultation with the EA and NII,
applicants should use the latest set of UK Climate Projections[11]
and the Government's latest national Climate Change Risk Assessment
when available, to ensure that they have identified appropriate
measures to adapt to the risks of climate change. Applicants should
apply as a minimum, the emissions scenario that the independent
Committee on Climate Change suggests the world is currently most
closely following—and the 10%, 50% and 90% estimate ranges.
These results should be considered by the applicant alongside
relevant research which is based on the climate change projections.
3.7.7 In addition the applicant should apply
the high-emissions scenario—high impact, low likelihood—to
those elements of their application that are critical to the safe
operation of the station.
3.7.8 Should a new set of UK Climate Projections
become available after the preparation of the ES, the IPC should
consider whether they need to request further information from
the applicant.
7. It is noted that a projection is essentially
meaningless—one can draw a straight line through any trend
and call it a projection. As long as a projection is not considered
to be a prediction or a forecast, then it is just speculation
and no weight should ever be attached to it in terms of planning
or risk assessment and mitigation.
8. With regard to the effect of climate
on nuclear power stations, the NII SAPS state:
208 External hazards include earthquake, aircraft
impact, extreme weather, electromagnetic interference (off-site
cause) and flooding as a result of extreme weather/climate change
(this list is not exhaustive).
226 The reasonably foreseeable effects of
climate change over the lifetime of the facility should be taken
into account.
703 The timing of decommissioning should be
considered on a case-by-case basis. Factors to be considered for
their relevance should include: p) future uncertainties including
climate change;
9. Thus use of the NII SAPS will ensure
that an applicant's safety case is based on a proper risk assessment
of all external hazards, which includes any hazards resulting
from changes to the climate. The NII does not prescribe what climate
model should be used in calculating the risk and in mitigating
the effect of the risk to make it ALARP. It is the responsibility
of the applicant to determine and justify the current and future
climate hazards that it should mitigate by design and operation
and justify in the safety case.
10. The safety case of the licensee is maintained
during operation through the Station Safety Report (SSR). This
is a living document, maintained up-to-date as the station and
its environment change. Similarly, the risks are maintained up-to-date
through use of a Living Probabilistic Safety Assessment (LPSA),
which accounts for changes to the station and its environment.
Furthermore, a Periodic Safety Review (PSR) is carried out by
the licensee every 10 years and continued operation requires
approval by the NII. Thus the safety of the station is maintained
ALARP by these non-prescriptive processes which will of necessity
include any environmental changes, regardless of the cause and
will use the best available sources of data.
11. In addition, the safety analysis performed
by applicants or vendors of nuclear power plants is performed
using configured, quality controlled computer codes which have
been verified and validated and which have acceptable documentation
consisting of user manuals and quality assurance manuals. The
UK climate model on which the UK Climate Projections are based
does not appear to be of the required quality to be used in a
safety case. It is stated[12]
that "We've taken the Met Office Hadley Centre
science as the basis for our projections and we've created 400 different
models from that, representing all that we know about the uncertainty
in our model. We've then, also, combined that information with
information from 12 international known models from around
the world, which have been in the Intergovernmental Panel on Climate
Change". Combining information from different models
is not a statistically valid procedure. Under no circumstances
should nuclear licensing be based upon the projections from a
combination of 13 different computer models with little in
the way of validation, verification, user manuals and quality
control.
12. Furthermore the UK Climate Projections
do not model external climate forcing:[13]
These scenarios assume no future changes in natural external
forcing, apart from a prescribed repetition of the 11 year
cycle of solar insolation based on past observations. It is
evident from a study of the UK Climate Projections that many non-evidence-based
assumptions are made and very little confidence can be placed
in the projections. Indeed the IPPC states[14]
Models continue to have significant limitations, such as in
their representation of clouds, which lead to uncertainties in
the magnitude and timing, as well as regional details, of predicted
climate change and it is known that cloud processes are
among the most difficult to simulate with models and cloud
feedbacks remain the largest source of uncertainty in climate
sensitivity estimates.
13. The revelations from the emails and
data leaked from the Climatic Research Unit (CRU) of the University
of East Anglia have cast considerable doubt upon the science behind
the hypothesis of man-made climate change, further under-mining
the validity of the climate projections.
14. Were applicants to follow the prescriptive
method of EN-6 which states at section 3.7.3: Climate
change is likely to mean that the UK will experience hotter, drier
summers and warmer wetter winters. There is a likelihood of increased
flooding, drought, heat waves, intense rainfall events and other
extreme weather events such as storms, as well as rising sea levels
and thereby ignore other potential changes to the climate,
there is a danger of underestimating the risks from external climatic
events. The ongoing extreme weather in the UK reinforces
the message that it would indeed be foolish to assume for safety
purposes that winters would be warmer and wetter.
15. For example, one area which the safety
case addresses is ensuring that staff can get to the power station
in extreme weather conditions, which includes snow storms, blizzards
and ice conditions and that the power station continues to be
operated within the boundaries of the safety case. The prescriptive
nature of section 3.7.3 of EN-6 suggests that the applicant
should ignore such winter conditions because we are going to experience
warmer wetter winters. Furthermore a cooler climate could
result in falling sea levels and the potential for a frozen sea
leading to loss of cooling water. A range of ambient cooling water
and air temperatures are justified within the safety case. The
analysis of such hazards should be addressed as part of the risk
assessment in the safety case as stated in the above SAPS and
not ignored as section 3.7.3 of EN-6 would appear to
be prescribing.
16. Section 3.4 of EN-6 correctly
identifies that the IPC does not get involved in the regulatory
process:
the IPC should make its decisions in relation
to a development consent application on the basis that:
— the relevant licensing and permitting
regimes will be properly applied and enforced;
— it does not need to consider matters
that are within the remit of the nuclear regulators.
and
The IPC should not review or revisit any regulatory
decision that has already been made in relation to the proposed
development. This will help to ensure that there is clarity and
clear division between the regimes for planning and regulation
of the nuclear industry.
17. A National Policy Statement should not
be used as vehicle to impose prescriptive licensing rules on applicants
for nuclear power stations.
PART 1—CONCLUSIONS
AND RECOMMENDATION
18. The current nuclear plant licensing
regime ensures that the safety case includes all risks and ensures
that the risks are maintained ALARP throughout the lifetime of
the plant. It is a dangerous precedent for a NPS such as EN-6,
to interfere prescriptively in the licensing process. The IPC
does not consider matters that are within the remit of the NII
as discussed in section 3.4 of EN-6. Section 3.7of EN-6 is
irrelevant to the IPC and should be deleted from EN-6. All references
to UK Climate Impacts Programme 2009(UKCIP) should be deleted
from EN-6.
PART 2—RADIOACTIVE
WASTE MANAGEMENT
19. I am in agreement with section 3.8 of
EN-6 concerning "higher level waste" (High Level
Waste (HLW) and Intermediate Level waste (ILW)) for the following
reasons:
— The major concern is the storage and
ultimate long term disposal of legacy waste. This is of no relevance
to the issue of the waste from a new fleet of nuclear power stations.
— The waste from a new fleet of new nuclear
power stations will be a minor contributor to the total waste
ultimately requiring long term disposal.
— The waste from a new fleet of new nuclear
power stations can be safely stored in on-site cooling water ponds
until such time as long term disposal is available. The activity
and heat load rapidly decay and the requirements in terms of cooling,
chemistry and security are simple and straight-forward. The alternative
to on-site ponds is transfer to on-site sealed casks in dry fuel
stores after a few years in a pond. The sealed casks are cooled
by natural air circulation. The casks have a design life of 100 years.
— It is inconceivable to imagine that by
the time ultimate long term storage of the waste from a new fleet
of new nuclear power stations is required (~120 years from
now for HLW), major technological advances will not have been
made. Better solutions will inevitably be found.
PART 2 —
CONCLUSIONS
20. The long term disposal of ILW and HLW
from a new fleet of nuclear power stations is not a significant
safety issue.
January 2010
6 http://www.hse.gov.uk/nuclear/saps/saps2006.pdf Back
7
http://news.hse.gov.uk/2008/04/08/nuclear-technical-assessment-guides-tags/ Back
8
http://www.hse.gov.uk/risk/theory/alarp.htm Back
9
http://www.hse.gov.uk/nuclear/tolerability.pdf Back
10
http://www.hse.gov.uk/nuclear/notesforapplicants.pdf Back
11
http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=163&Itemid=287 Back
12
http://www.metoffice.gov.uk/climatechange/guide/ukcp/dr_vicky_pope_talk_about_ukcp09_transcript.pdf Back
13
http://ukclimateprojections.defra.gov.uk/content/view/2036/517/ Back
14
http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-chapter8.pdf Back
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