Author: Keith Pearce

Costs of decommissioning UK nuclear industry

cost of decommissioining

The NDA have issued a statement on the estimated costs of decommissioning the parts of the UK nuclear industry that they are responsible for (here).

It shows total costs in the range £97 billion – £222 billion with a best estimate of £119 billion over 120 years. Discounted cost is put at £164 billion which is higher than the unadjusted cost because the NDA now use negative discounting rates as explaining in the supporting document from the Treasury (here) but more clearly in an Annex to the Annual Report (here).

The current value of £164 billion compares to £160.6 billion a year ago. This includes £1.3 billion being added to the estimated cost of completing the job. Inflation and changes to the discount rates being applied explains the rest of the increase.

So despite £3.243 billion being spent and an Annual Report talking of good progress the estimated cost to completion is more than it was at the start of the reporting period.

The Annual Report admits that £100 million was spent in compensation following the flawed contest for the Magnox contract.

 

 

A Korean APR 1400 for Moorside?

It looks possible that the Korean company TEPCO will take a major stake in the Moorside project. This may involve junking the design and regulatory  work already done on the UK AP1000 (Ref ONR Website) applying to build their own APR 1400 design. That may cause delays but they have a good record of building reactors.

Kepco was formed in 1951, has the brand statement “power with heart” and describes its main business as “Electric power, heat supply, telecommunications and gas supply” (Ref KEPCO website). According to Wikipedia it is just over 50% state owned.

Early news of TEPCO’s interest in Moorside was published in the Guardian in February 2017 (Ref)  More recent news is reported in the FT in July 2017 (Ref). New investment is thought necessary as Toshiba is struggling to survive (Ref).

Korea has a very credible history in the nuclear industry (Ref). The APR1400 being built at Barakah in Abu Dhabi is reported to be 95% complete and receiving nuclear fuel (Ref). But the news that Korea is withdrawing from nuclear power at home (Ref) is a cause for concern.

A one page overview of the APR 1400 reactor can be found at Ref  and a more detailed one at Ref. (See also Ref for a description of the APR+).

The first of these reactors, Shin Kori Unit 3, entered service in December 2016. Reports suggest that 7 further units are under construction and 4 more planned (Ref)) although the recent announcement of a plan to wind down domestic nuclear power (Ref) may have an impact on that programme.

The APR1400 is a 1450 MWe evolutionary PWR based on the Korean Standard Nuclear Power Plant (KSNP) aspiring to provide both enhanced safety and economic competitiveness.

As shown in the circuit diagram below the reactor design has two steam generators but, unusually each of these has two reactor coolant pumps each feeding into a separate cold leg. The pressuriser, attached to one hot leg, and the steam generators are increased in size compared to previous models and the reactor outlet temperature has been dropped to cope better with transients.

From IAEA-CN-164-3S09

Leak before break technology has permitted the pipe restraint system to the simplified.

The Safety Injection System consists of four trains each with a safety injection tank and a safety injection pump. This system provides high pressure, low pressure and recirculation in one system. It injects directly into the Reactor Pressure Vessel to eliminate the potential for leakage from a damaged cold leg. The safety injection pumps are physically separated from each other reducing the probability of common mode failure in fires, sabotage or floods.

A steel lined, post tensioned concrete structure with a reinforced concrete internal layer provides containment, biological shielding and protection from external hazards. It contains the reactor, the reactor cooling circuits, the steam generators and the In-Containment Refuelling Water Storage Plant. The latter is a key safety feature providing cooling water in fault conditions and a large heat sink.

Interestingly the reactor is designed to be able to manage daily load following based on the Korean experience of demand of 100% output for 16 hours a day and 50% output for 4 hours a day with 2 hour power-ramps.

The financial case for Hinkley Point C

The government have updated their contractual documents and supporting information for Hinkley Point C (here).

The decision taken by the Secretary of State (SoS) for the Department of Business, Energy & Industrial Strategy to direct the Low Carbon Contracts Company (LCCC) to offer a Contract for Difference (CfD) to Hinkley Point C was based on the Value for Money Assessment published on this site. This means that the Government will reimburse the operators if they have to sell electricity below the “strike price”.

This is based on the belief that, left to themselves, “market failures” would result in a undesirable configuration of the electrical generation and distribution system.

Businesses are more likely to invest where the return on capital is rapid and secure. In the electrical generation world this means gas turbines and other cheap and quick to install kit. The current designs of nuclear reactors under construction are far from this ideal. Expensive, with long lead times and technical and political risks involved. The investor has to put in a lot of money upfront and wait a long time for returns. A technical or political hitch could wipe those returns out at any time. A principle of the CfD justification is that the investor should get a fair return for risking their capital over a long period of time on a “first of class” power station. It is a risk sharing mechanism that saves the government from direct investment in the project.

The market does not fully take into account the real societal costs from burning hydrocarbons and by itself would not reduce the production of greenhouse gases associated with fossil fuel combustion. So subsidies are given to low carbon generators to bridge this unfairness. This is an area of controversy with some believing that all subsidies are wrong and others wanting them only for their preferred version of “green”. Nonetheless some of the CfD is to encourage low carbon generation.

Another consideration is diversity of supply. It is true that the British people and the British economy would be unhappy if their energy needs were more expensive than needed but they would be far more unhappy if their energy aspirations were not met. Imagine flicking the light switch and nothing happening. A large nuclear power station can provide base load electricity day in day out no matter what the weather and is slow to be affected by any disruptions in the fuel supply. This will be valuable in a future with more dependence on imported hydrocarbons and larger amounts of wind and solar power but where storage of electricity on the scale desired to stabilise a renewables dominated grid is technically and financially out of reach.

The case is laid out for all to read. Some say the strike price is too high, some say far too high. It remains to be seen if Hinkley Point C can and will be built and whether the investors will get a decent (or maybe indecent) return on capital invested.

 

 

Heatwave plan for England

PHE and NHS England have issued new advice on planning for heatwaves (here).

The purpose of this heatwave plan is to reduce summer deaths and illness by raising public awareness and triggering actions in the NHS, public health, social care and other community and voluntary organisations to support people who have health, housing or economic circumstances that increase their vulnerability to heat.

It states a concern that periods of hot weather will become more common in the UK as climate change kicks in leading to increased deaths among several identified vulnerable groups and some infrastructure issues.

The Met. Office has a mechanism for promulgating alerts about forecasts of dangerous weather conditions and this is explained in the context of heatwaves and is linked to five levels of heatwave readiness.

We should be trying to make our public spaces, buildings and homes cooler by design, including tree planting and open water features. Cooling homes by appropriate shading and ventilation but also by choice of colours for curtains and roofs.

On the day we should be avoiding exercise in the midday sun, drinking plenty of water but less caffeine, wearing cool clothing and looking out for our neighbours.

It is a bit light on what employers can do to protect their workforce without sacrificing more productivity than required but, if they read the report, they’ll pick up some useful tips.

Communicating the risks of particulate and chemical air pollution and air-borne radioactivity.

There is an interesting article “Cutting through the smog” by Nic Fleming in the 6th May 2017 New Scientist. There are some scare statistics given – “it is estimated to be behind 200,000 untimely deaths each year”. But, as the author points out quantifying the impact of air pollution is a more complicated and uncertain business than the headlines admit.

There are parallels with the issues of environmental radioactivity and distrust of the nuclear industry.

Air pollution and radioactivity do not kill in the same way as being hit by a London bus might. Air pollution may aggravate other problems you have and has been linked to respiratory and pulmonary diseases and stroke. A UK committee has estimated that the anthropogenic PM2.5 released at 2008 levels would shorten the average person’s life by six months. This is morphed into costing 29,000 deaths a year in the UK, which is the major headline carried by the media.

Similarly radiation, in low doses, does not lead to instantly noticeable effects but rather is suspected of leading to an increase in the incidence of cancer in later years. Quantifying the additional cancer risks posed by different types of radiation at different doses, different dose rates and on people with different inherent cancer risks is complex and usually, by necessity, over simplified when attempting to explain it to the public. ICRP states that the linear no-threshold hypothesis “remains a prudent basis for radiation protection at low doses and low dose rates” but there is also an increasingly strong insistence that there is some kind of a threshold at 100 mSv. (See IAEA EPR Communicate).

In the UK it is the local authorities that are tasked with implementation of the national air quality strategy. The Lancet  fears that this will lead to a fragmented approach “as hundreds of local authorities (tasked with implementation) attempt to follow central government guidelines” and they doubt the “the ability of the government to measure progress and hold failing local authorities to account”.

Unfortunately the steps taken to reduce air pollution, particularly in cities, have always struggled to keep up with increased road usage and, particularly, increased use of diesel engines. The New Scientist report questions the effectiveness of the London Low Emission in reducing levels of pollutants or related respiratory and allergy problems in children despite its wide scope. Encouraging more people to walk or cycle and providing low emission public transport would seem to have just reduced the rate of increase of vehicle mileage in cities. Well worth doing but not enough. It is noted in the article that emissions of a number of key pollutants in the UK are dropping, for some quite dramatically. But more progress is desired.

The report claims that face masks vary from about 80% to 30% effectiveness at filtering particles from the air but it depends on the nature of the mask, the nature of the pollution and, importantly, the quality of the fit to the face of the mask. Unless they are treated with appropriate chemicals the masks have no impact on gaseous pollutants such as NO2 and SO2. Face masks are not recommended in the UK as an effective countermeasure against inhaled radioactivity in the event of a reactor accident because of concerns about their effectiveness without face fitting and training and because the principle component of concern are the radioactive iodine species. The preferred approach is to remove the person from the threat by sheltering or evacuation. For a non-technical discussion about face masks see an article by the survival mom and the comments attached to it.

A difference between air pollution and environmental radioactivity is that the public do not seem to fear air pollution to quite the same extent. Shunichi Yamashita reflects on the situation around Chernobyl and Fukushima following the two severe accidents in those places in the New Scientist of 13 May 2017. He reports that the big surge in non-thyroid cancers and genetic effects in the areas affected by Chernobyl that some predicted have not been detected. His advice to people in Fukushima in the early aftermath of the accident there, which was to try to relax and to try not to worry about the enhanced environmental radioactivity, was widely condemned but he still contends that he would expect no apparent health effects when the exposure was below 100 millisieverts a year. (I’m not sure about the “a year” bit, it might be a misunderstanding. ICRP advice is that a one-off residual dose of 100 mSv is probably not harmful but that the dose-rate thereafter should be no more than 20 mSv a year. (See ICRP letter to Fukushima residents).

The article concludes that psychological effects from the trauma of evacuation and the fear of radiation are now the biggest health consequences of the nuclear accident at Fukushima. Adults are experiencing depression, sleep loss and anxiety. There have been more than 80 suicides linked to the accident to add to the 60 people who died due to poor medical support during the evacuation. But there have been no deaths or sickness from direct exposure to radiation.

The conclusion from comparing the articles on air quality and post-Fukushima health concerns is that understanding the impact of airborne pollutants including ozone, particulates, NOx and SOx and radioactivity is very difficult. Communicating those potential impacts to the public is also very difficult but also very important. Without an understanding of the relative impacts of different aspects of modern life it is not possible for the public to understand the absolute and relative risks posed or for governments to sensibly prioritise policy and funding.

Strategic National Guidance: Decontamination of buildings after CBRN incident

Decontam

This document states that it is important to have plans in place to manage the decontamination of the environment (built and natural) following a CBRN event or accident that spreads contamination. This is sensible at national levels but the report states that “The possibility of exposure to CBRN should be a key component of business continuity planning (BCP) in order to maximise resilience, safeguard life and property, and minimise operational disruption”.

This is taking things too far. Many Business Continuity Managers complain that they can’t get support for the maintenance of plans against things that might reasonably be expected to happen. I’m really not sure that we can expect companies and households to have CBRN decontamination plans.

https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/600715/SNG_5thEdition_Final_March_2017.pdf

Notification of Withdrawal Bill and Euratom

One paragraph of the European Union (Notification of Withdrawal) Bill Explanatory Notes states that “The power that is provided by clause 1(1) applies to withdrawal from the EU. This includes the European Atomic Energy Community (‘Euratom’), as the European Union (Amendment) Act 2008 sets out that the term “EU” includes (as the context permits or requires) Euratom (section 3(2)).”

It would be interesting to know what the impact on the UK nuclear industry might be if the UK were to withdraw from Euratom. It would give us more freedoms to run the industry as we see fit but that may not be such a great idea and it might reduce public and world confidence in us. There are, of course, many other international nuclear organisations such as IAEA and WANO that we can use for guidance and bench marking.

The revision of REPPIR

With the Radiation (Emergency Preparedness and Public Information) Regulations 2001 due to be reissued in line with the 2013 EU BSS (See HSE note), interest turns to the discussion about how to determine the appropriate level of emergency preparedness for nuclear sites.

Currently REPPIR requires that the risks posed by the site are assessed, reported and periodically reviewed. If there are identified potential fault sequences that exceed thresholds of both probability and severity then off-site plans are required.

The threshold for probability is “reasonably foreseeable”. In the REPPIR guidance (para 50) it is stated that “In the context of a radiation emergency, a reasonably foreseeable event would be one which was less than likely but realistically possible”. ONR have avoided accepting a numerical value for the threshold of reasonably foreseeable (see, for example, para A20 -A22 in an ONR TAG).

ONR’s description of safety cases tells us that (Para 607) Design basis analysis (DBA) leads to an understanding of the plant and a design proven “so that safety functions can be delivered reliably during all modes of operation and under reasonably foreseeable faults”. Combining this with (Para A.9) “only faults with an initiating fault frequency (IFF) greater than 1 x 10-5/yr need to be considered for DBA” suggests that a frequency of 1 x 10-5/yr could be proposed as the limit of a “reasonably foreseeable” initiator.

1 x 10-5 per year is also implied in the ONR Tolerability of Risk Document ToR and in the national risk assessment policy sponsored by the Cabinet Office as a boundary between events that should be prepared for and those that are too unlikely for detailed planning.

The threshold for severity used in REPPIR 2001 is that of a Radiation Emergency. This is defined as a situation in which a member of the public could receive an additional radiation dose of 5 mSv in the year following initiation. There have been difficulties interpreting this requirement as the public dose assessment depends on the individual habits assumed.

There is a general principle in radiological protection and emergency planning that any action taken by authorities should to do more good than harm. In the UK we use the Emergency Reference levels (ERLs) to decide if a countermeasure is warranted by comparing the avertable dose with the relevant ERL. We can therefore state that the imposition of a countermeasure is not necessary, indeed not appropriate, where the avertable dose is below the ERL and a detailed plan to implement a countermeasure is therefore not needed where it is not reasonably foreseeable that the threshold will be exceeded. Thus the severity threshold for requiring a plan can be based on whether or not the existence of a plan would enable the imposition of prompt countermeasures which could avert an ERL’s worth of dose that could not otherwise be averted.

Concern about faults too unlikely to appear in the DBA but more severe than the reference accidents leads to the demand for the ability to extend countermeasures beyond the detailed plan if required. However, it is realised that spend to enable this quickly becomes grossly disproportionate to the potential gain.

While the situation analysis and decision making process provided by the detailed plan can consider a wider area or longer duration fault, the question is whether or not countermeasures can be applied rapidly enough over a wider area to be effective. This would depend on the nature of the fault including the amount of activity released and the time structure of that release.

Again the question of the probability of the limiting fault to use in extendibility scenarios arises. In various safety methodology documents IAEA talks about a “screening probability level” (SPL) of probability below which there is no point analysing faults. So far as I can find IAEA fails to suggest a value. There is a claim in the literature that the US DOE suggest 1 x 10-6 for aircraft crash onto nuclear facilities. It is suggested that future UK guidance on emergency planning recommends a SPL for emergency planning (extendibility) and that this value should not be lower than 1 x 10-6 or, at a pinch, 1 x 10-7.

Emergency planning then becomes a question of having detailed plans to implement those countermeasures that might avert more than an ERL of individual dose for the set of reasonably foreseeable faults – defined as being more frequent than 1 x 10-5 per reactor year (making allowances for reasonable cliff-edges) and outline plans for faults down to maybe 1 x 10-7 per reactor year. Estimations of avertable dose against downwind distance can determine a sensible limit to the countermeasure zone (which regulators may then choose to inflate within reason for non-technical purposes).

Major step towards decommissioning Magnox’s emergency plan

The ONR has recently agreed to a major revision of the Magnox Limit’s emergency plans. In a Project Assessment Report available on the internet they approve the removal of the Central Emergency Support Centre (CESC) from the Magnox emergency plans.

The CESC is a large control room in EDF’s headquarters in Barnwood. It provides for the off-site support for a nuclear power station in an emergency situation. Command, technical, health physics and support teams are available at short notice during working hours and within an hour or so out of hours. The technical team helps to understand the situation on the site and provide advice on how to rectify the situation and on the release prognosis. The health physics team takes over the off-site survey and combines the knowledge gained about off-site doses with the predictions of the changing situation from the technical team to provide estimates of the public avertable dose to support the countermeasure decision process in the Strategic Coordination Centre.

With no operating reactors and most of the fleet defueled the changes of Magnox using this facility is greatly reduced. They have developed a new simplified system that is more in line with the evolving Company risk profile and tested it to the satisfaction of the ONR.

EDF-Energy, with their fleet of operating reactors will continue to use the CESC.

Removal of the CESC from the Magnox plans is an important step and was a complex process. Magnox and the ONR should be congratulated on the success of this project.