Please could you ask the ONR for sight of their joint evaluations with other government bodies of the seismic impacts of the onshore and offshore coal mine to Sellafield including the worst-case scenario seismic impacts from:
Has the ONR asked for any independent assessments from non-governmental bodies?
Will the ONR be willing to release these joint studies? Has the ONR requested independent assessments?
I can confirm that ONR holds the information requested by and that the relevant documents, along with our previous correspondence on this matter, are attached to this response. In summary, ONR is entirely satisfied, based upon robust and independent evidence, that coal mining in West Cumbria does not pose any risk to safety at Sellafield.
We have identified five relevant documents which are drawn from ONR’s consultations with the British Geological Survey (BGS), HM Inspectorate of Mines (HMIM), and the ONR Expert Panel on Natural Hazards. Any redactions are of personal data and have been withheld under Section 40 of the FOIA.
A summary of each document is provided below and I trust that they, in addition to the information already provided, assure you and that we are actively engaged in the fulfilment of all of our responsibilities in these matters, and provide additional confidence that ONR has taken and continues to take these concerns seriously.
Document One sets out a sequence of emails between ONR and HMIM in examining the concerns regarding the likelihood of seismic impact and potential consequences. ONR first received concerns from Radiation Free Lakeland on 23 August 2018 and subsequently sought advice from HMIM and the ONR Expert Panel on Natural Hazards.
As you will be aware, the nature of the mining methodology is such that it is designed to not collapse at any foreseeable point in the future, meaning there is far less effect on the surrounding strata and on the sea bed than the ‘caving’ method used previously.
Therefore, the advice from the panel is that the proposed new subsea coal mine is not considered to be capable of generating ground motions that would affect safety at the Sellafield site. This conclusion was used to inform ONR’s response of 6 December 2018 to Radiation Free Lakeland.
Due to the importance of the concerns raised in Radiation Free Lakeland’s initial email of 23 August 2018, ONR also consulted with BGS to seek additional assurance.
The BGS carried out a quantitative assessment of ground motion predictions, confirming that even for larger magnitude events, not deemed credible for this proposed mining method, very low levels of ground shaking are still predicted (see the table of results produced at Document Two). These motions would not disrupt structures, systems and components important to safety on the Sellafield site, and as confirmed by ONR’s Expert Panel, certainly would not contain sufficient energy to present any liquefaction risk.
After receiving additional queries from Radiation Free Lakeland in a second email on 13 January 2019, ONR consulted with the ONR Expert Panel on Natural Hazards again on the potential of mining-induced seismicity near Sellafield. This paper was produced by Professor Julian Bommer of Imperial College London and was used to inform ONR’s response of 6 February 2019. Professor Bommer is a member of the specialist sub-panel on Seismic Hazards, and his specialist expertise is in engineering seismology. This paper was used to inform ONR’s response of 6 February 2019 to Radiation Free Lakeland, and address comparisons made to the fracking industry.
Document Four sets out a sequence of emails between HMIM and ONR in examining the concerns raised on distances, proposed mining methods, and comparisons to the fracking industry in Radiation Free Lakeland’s second email. The queries to HMIM are set out in the red text and their responses in blue in the email dated 18 January 2019.
Following your latest request for information concerning worst case scenario seismic impacts, we again contacted HMIM for specific comment and to clarify the level of risks posed by the three activities you mentioned: coal extraction, backfilling of the voids with cement, and coal washing. Document Five sets out the sequence of emails in seeking HMIM’s advice. Their response, as you can see, was that these activities do not generate any significant or any seismic effect.
Finally, asked whether ONR has asked for any independent assessments. After careful consideration, we concluded that it was not necessary on this occasion to seek any further input. This was because the advice received from the ONR Expert Panel on Natural Hazards, HMIM and the BGS was considered to be sufficiently thorough and robust. This panel is a group of independent leading academics and specialist consultants covering a range of skill areas relevant to seismic and coastal flooding hazards and climate change.
ONR and the experts consulted have thoroughly examined the concerns brought to our attention by ‘Radiation Free Lakeland’ and we are satisfied that the level of seismic risk arising from the proposed coal mine is extremely low.
Thank you for your correspondence and for your interest in ONR’s work. I hope that this comprehensive reply gives you, and confidence in the approach ONR has taken to secure and verify the scientific evidence available.