Radiation exposure (to workers and the general public)
We are committed to maintain a comprehensive radiological protection programme safeguarding all our employees and contractors and the general public against the hazards of ionising radiation arising from operating our plants. Our approach is to ensure as a minimum, compliance with all applicable regulations, to emulate best nuclear industry practices and continuously improve our practices and to work to a common fleet standard. We strive to ensure that any radiation exposure to ionising radiation is kept as low as reasonably practicable (ALARP), to reduce individual and collective radiation doses and prevent any worker exceeding a statutory radiation dose limit.
Radiation dose to the public
The main source of radiation dose to the public from our operations is the impact of radioactive discharges to the environment. Therefore radiation dose to the public is a function of our Environmental Policy. We are committed to demonstrate high standards of performance in the way we ensure safety and protect the environment. Recognising our duty to care for the environment, we have a special obligation to assure our nuclear power stations are operated in a manner that safeguards the public and the environment.
Our goal is to achieve excellent environmental performance, recognising that compliance with regulations is not enough on its own to achieve excellence and holding ourselves to a higher standard.
We seek continuous improvement in our environmental performance and comply with all applicable legal and other requirements, by:
- Reducing the environmental effect of our activities, products and services to a practicable minimum by the prevention of pollution, reduction of waste and the efficient use of resources;
- Promoting the efficient use of energy;
- Continuing to develop a sense of environmental responsibility among staff and contractors;
- Openly reporting performance against environmental targets;
- Assessing the impact of our operations on biodiversity and implementing opportunities for enhancement.
Our policy includes adherence to the following standards:
- Clear compliance criteria are defined for all environmental permits, authorisations and consents, that if met will ensure we remain within the strict requirements of the regulations.
- Best Practicable Means are used where required.
- Clear and documented support is obtained from the environmental regulatory bodies for our interpretation of their environmental permits, authorisations and consents.
- We work with the environmental regulators to ensure our permits, authorisations and consents are based on sound science and are documented to avoid uncertainty in scope or interpretation.
- Activities are planned, specified and implemented in a manner to achieve environmental excellence.
- Plant is operated within the bounds of permits, authorisations, consents and other applicable environmental regulations.
- Plant design and operating margins are recognised and carefully guarded at all times by investigating and resolving problems promptly.
- Equipment is maintained so that it can perform fully as required in permits, authorisations and consents and other applicable environmental regulations.
- Operational decisions and actions are based upon the need to maintain margins of compliance to environmental limits. Decisions are made, based on the fullest information available, toward a long-term view of operation.
- A positive culture is fostered within Nuclear Generation, characterised by communications founded upon mutual trust and by shared values that recognise the importance of excellent environmental performance.
Radiological protection is identified as one of the 15 principle processes within our Company.
We have dedicated radiological protection personnel and a radiological protection programme in place to set standards, measure compliance and drive continuous improvement. Many of the improvements that have been introduced over the last six years would not have been possible without management support and financial investment in the radiological protection programme.
We have adopted a ’programme of health’ based on WANO’s performance objectives and criteria, together with a set of performance metrics that are reviewed and reported quarterly. Regulatory compliance is monitored by an internal control process linked to the ‘programme of health’. Anomalies that are identified are analysed, reported and addressed.
Our radiological protection improvement plan focuses on processes, training, instrumentation, manpower and benchmarking. The plan is aimed at addressing performance gaps and replicating best practices across the fleet. We measure delivery and station implementation.
Independent corporate surveillances are undertaken at stations to assess the adequacy of radiological protection outage programme control measures and to assess progress to implement radiological protection improvement plans to the fleet standard.
Radiological protection of workers is paramount in the planning and execution of work involving ionising radiation. Work is fully justified in terms of its net benefit and risks from work with ionising radiations are assessed within a formal process linked to all work performed. A radiological risk assessment is performed for each task performed inside the Radiological Controlled Area by a radiation safety engineer and radiological safety work permits are issued to personnel that specify radiological precautions. All work activities are planned, specified and implemented in such a manner as to ensure that individual and collective radiation doses are maintained as low as reasonably practicable (ALARP).
Training and instruction is provided to equip workers with the knowledge required to work safely in Radiological Controlled Areas. Workers undergo induction training and job orientation. In addition, simulator training has been developed to train personnel and contractors to an agreed standard covering fundamental requirements for working in and exiting contamination areas. Mock up training facilities have also been provided which simulate the reactor and plant. These help to train workers to safely execute work in high risk radiological areas. This training has resulted in improved standards and has contributed to reducing the radiation dose that workers receive.
Controls and supervision are provided to oversee the safety of persons required to enter Radiological Controlled Areas. A ‘meet and greet’ programme has been implemented at the entrance to Radiological Controlled Areas to assess whether workers fully understand the radiological safety requirements for their intended work.
Coaching is encouraged in Radiation Controlled Areas to correct sub-standard practices and behaviours and radiological protection coaching cards and a coaching database have been introduced.
Workers are expected to adhere to radiological protection rules, minimise the dose they accrue, limit the generation of radioactive waste and to correctly use Personal Protective Equipment and monitoring instrumentation.
Any workers who purposely disregard radiological protection rules or instructions will, in the interest of their own and other workers’ safety, be barred from entering Radiological Controlled Areas until their management has instituted remedial action to prevent a recurrence.
Whenever practicable, engineered and physical control measures are employed to minimise radiological risks in the work place.
Adequate radiological protection monitoring instrumentation and Personal Protective Equipment is provided to ensure the safety of workers. An instrumentation replacement programme was instigated, for installed and portable radiation and contamination instrumentation, to provide an improved monitoring capability. Obsolescent personal contamination exit monitors were replaced at all sites in 2011. The new exit monitors are far more sensitive and their settings are aligned to international standards.
Portable radiological protection instrumentation has systematically been replaced to a common fleet standard. Improved Personal Protective Equipment for work in Radiological Controlled Areas is progressively being replenished by all stations.
All sites use an Electronic Personal Dosemeter which measures radiation dose and warns the wearer if pre-determined dose levels are exceeded. Teledosimetry systems, which can be used to remotely monitor the dose received by workers, have been introduced for work in high radiation dose rate areas.
Tool stores are being established to limit the quantity of equipment taken into the Radiological Controlled Areas. This improvement reduces the manpower required to monitor and clear the equipment from the areas and lowers the risk of inadvertently releasing contaminated equipment.
Together with our contract radiography companies there is alignment with new standards for radiography, that incorporates industry best practices (such as close proximity radiography) with training and learning points from past radiography events. In 2011, 76% of radiography inspection work was undertaken by close proximity radiography which significantly reduces the radiation risk from this type of work.
Corporate and station ALARP committees periodically review radiological performance with the objective of improving radiological protection standards and reducing radiation dose to workers.
We have never had an incident resulting in a significant uptake of radioactivity by a worker and no worker has received a radiation dose above the legal limit. In the unlikely event that a worker be exposed to a dose above the statutory dose limit reporting procedures are in place and specialist staff would be engaged in counselling the individual about the dose received. However at these levels no specialist treatment would be required. Should the dose to the individual be truly excessive then there are specialist hospitals designated for the treatment of casualties exposed to very high levels of radiation and the individual would be referred to one of these for treatment.
EDF Energy station collective radiation dose performance is among the best in the international nuclear industry.
Radiation dose to the public
The main source of radiation dose to the public from our operations is the impact of radioactive discharges to the environment. Therefore, our Environmental Management System is the most relevant to radiation dose to the public. We identify and plan those operations that are associated with the identified significant environmental aspects consistent with its environmental policy, objectives and targets, in order to ensure that they are carried out under specified conditions by:
- Establishing, implementing and maintaining a documented procedure(s) to control situations where their absence could lead to deviations from the environmental policy, objectives and targets;
- Stipulating operating criteria in the procedure(s); and
- Establishing, implementing and maintaining procedures related to the identified significant environmental aspects of goods and services used by EDF Energy Nuclear Generation and communicating applicable procedures and requirements to suppliers, including contractors.
Each operational site has Environmental Specifications (ESpecs) that are the mechanism for satisfying the above requirements in the Central Control Room. These cover both radiological and non-radiological processes.
Each operational site has an Environmental Maintenance, Inspection and Testing Schedule (EMITS) associated with environmentally sensitive plant and significant aspects.
We subscribe to a number of other non-legislative other requirements e.g. The Nuclear Sector Plan (a collaborative project between the Environment Agency and the whole nuclear industry that plans to reduce the impact of the nuclear sector on all aspects of the environment, going well beyond the requirements of environmental legislation), ISO14001 and Biodiversity Action Plans.
The company’s Environmental Management System (EMS), and all its supporting specifications, forms part of the Company Management System and utilises recognised company processes where practicable.
Broadly there are two types of environmental documents that make up the EMS. The first type describes specific environmental processes that are generally applicable to all environmental regimes e.g. maintenance and operation of equipment and training of staff. The second type specifies how the company complies with particular “major” environmental legislation.
Each site maintains documented procedures to monitor and measure, on a regular basis, the key characteristics of its operations and activities that can have a significant environmental impact.
The procedure(s) include the recording of information to monitor performance, applicable operational controls and conformity with the Company’s environmental objectives and targets.
Centrally, the Environment Department monitors, measures and reports each site’s and the overall fleet environmental performance.
Radiation exposure (to workers and the general public)
Collective Radiation Exposure (Dose)
We operate to strict procedures to minimise, reduce and control the radiation doses received by all our employees and contractors at all of our nuclear power stations. Any worker required to enter a radiological controlled area is issued with an electronic personal dosemeter which measures radiation dose and warns the wearer if pre-determined dose levels are exceeded. Radiation dose is measured in units of milliSieverts (mSv). The legal dose limit is 20 mSv per year and we operate to a Company Dose Restriction Level of 10 mSv.
In calendar year 2012, the average individual dose received by all our employees and contractors on our sites was 0.119 mSv (this is 0.6% of the legal limit).
The highest individual dose received on our sites was 8.179 mSv in calendar year 2012 (this is 41% of the legal limit). In AGR vessel outage years we incur higher individual dose due to the nature of the work being performed. This dose was received by an AGR in vessel inspector who had to perform inspections across all three AGR reactor in vessel campaigns.
Radiological protection performance on EDF Energy NG sites has continued to exhibit year on year improvement with respect to radiation exposure. The principle reason being the governance taken for work associated with the highest impact on Company Collective Radiation Exposure. Simulator training facilities, procurement and use of improved equipment, coupled with a highly trained and experienced workforce has resulted in better than anticipated improvements in 2012. Most significant reductions have been for AGR reactor in vessel work at Hunterston B and Hinkley Point B where minimal repairs to improve the safety of the boilers, was required. It should be noted that a requirement to perform AGR in vessel work was necessary at Torness to inspect and repair a standpipe. In addition to the stringent dose budget for AGR in vessel work, there was an overall reduction in collective radiation exposure across all AGRs. This is an excellent achievement bearing in mind the work and dose targets set for calendar year 2012. The collective radiation exposure at Sizewell B (PWR) in 2012 is the lowest annual collective radiation exposure for Sizewell B over the last 8 years.
The three year average yearly WANO Collective Radiation Exposure (dose) for EDF Energy Nuclear Generation at the end of 2012 was 0.069 manSv/reactor versus a target of 0.076 Sv/reactor. There is no legal or international limit on this measure. We are striving to show a continuous improvement (reduction) in this key performance record as demonstrated by the annual improvement in our performance over the last 3 years.
Dose to the Most Exposed Members of the Public
We are required to assess the radiation dose to the most exposed members of the public in the vicinity of our sites using the results of environmental monitoring. However, this does not distinguish between the impact of our discharges and those of neighbouring operators. Discharge modelling is used to make a conservative assessment of the impact of our discharges on the local population; the assessment for the three years 2010 to 2012 is given below.
Doses to the public are a very small fraction of the legal limit and the average radiation dose due to natural background in the UK. The maximum dose received over this period (0.006 mSv in 2012) is equivalent to the natural radiation dose received during a single flight from London to Rome.
The consistent level of very low public dose from 2010 to 2012 is evidence of the Company’s successful efforts to employ best practicable means to minimise the impact of its discharges on the public (a formal requirement of our discharge permits).