Biogenic metal phosphates: Low cost, high capacity, stable 'lockups' for the removal of radionuclides from groundwater and decontamination solutions

The development of nuclear weapons and energy programmes since the 1940s have created a legacy of nuclear waste and contamination worldwide. In 2012, Sellafield Limited (named as the most hazardous nuclear site in the UK) hit the national press/media when a report by the National Audit Office highlighted the considerable challenges and spiralling costs faced by the UKs Nuclear Decommissioning Authority in taking forward the cleanup of this site. In 2012, the Fukushima Daiichi power plant and surrounding contaminated area (650 km2) also recently hit international news headlines when Tokyo Electric Power Company confirmed the accidental release of 300 tonnes of highly radioactive and concentrated waste water into the Pacific Ocean. An ice wall costing £300m has been pledged to prevent groundwater flow through the most contaminated reactor site but there are still plumes of contaminated groundwater that need to be treated and the decontamination of soil (estimated at 60 Mt) will produce even more complex liquid waste.

British Nuclear Fuels invested in 30 years supply of naturally occurring zeolites (clinoptilolite) to remove aqueous Cs+ and Sr2+ from fuel cooling ponds. However, legacy and accidental waste is more complex (e.g. saline wastewater, complex and high organic soil decontamination solutions from Fukushima; and lower radionuclides concentrations and high background competing ions in Sellafield groundwater). Zeolites are inefficient under these conditions (e.g. lower sorption capacity and/or low mechanical strength), therefore, new innovative technologies are required for the safe remediation (cleanup) and entrapment (lockup) of radionuclides from these complex contaminated waters.

Under complex chemical conditions, microbially-generated, rapidly produced biominerals have high metal adsorption capacity/functionality compared to natural zeolites and commercially available/laboratory grade materials, arising from their unique morphology and nanoscale properties. For example, biogenic hydroxyapatite materials (HA mass more than ten times the mass of the bacteria that produced it) have durable radionuclide adsorption capacity (up to 30 %wt for radionuclides tested: Actinides (U, Am), Sr and Co under simulated groundwater conditions, against high concentrations of competing ions (0.1-2000 mmol/L Na+, Cl-, Ca2+, Mg2+) and at wide ranging pH conditions (3-9.5); the specific nanostructured morphology of Bio-HA was shown to underlie these advantages. Bio-HA also has proven superior stability against metal remobilisation, economics, & function as compared to commercially available materials and, being biogenic will never run out or require procurement or import from other countries (enabling stable-supply and rapid-response). Additionally we have produced a new Bio-CeP material that shows great promise for Cs remediation. However, both biominerals have not been tested or applied as a permeable reactive barrier or ion exchange technology using environmental conditions found at contaminated sites.

The grant will be held at the University of Birmingham, which has an established track record in nuclear research dating back to 1950s, (specifically, nowadays, in remediation, decommissioning, health monitoring and residual life prediction for existing nuclear power stations) and recently led a Policy Commission into the future of nuclear energy in the UK. The grant will also be supported by the National Nuclear Laboratory and the Japanese Atomic Energy Authority enabling the achievement of technology readiness level four, rapid worldwide dissemination of research outcomes and increased societal impact.

The aim of this bid is to advance biominerals (Bio-HA and Bio-CP) to technology readiness level (TRL) 4, thereby bringing this technology a step closer to field scale application for the cleanup and durable 'lock up' of radioactive contaminants. This will have relevant applications to worldwide contaminated such as Sellafield sites (UK) Hanford (USA) and Fukushima (Japan), with the project being a partnership between the National Nuclear Laboratory (UK) and Japan Atomic Energy Agency.

Academically, this project will impact strongly on researchers working in environmental science, materials science and environmental engineering. The scientific outcomes will inform/inspire scientific peers via high impact and open access publications and by presenting research outcomes at topic-specific international and European conferences. Biomimetic research is also an area that will benefit (by using Serratia sp as a model organism and full characterisation of materials), future synthetic minerals that could be produced with the same superior quality (higher sorption capacity and nanostructured) as biogenic minerals.

The aims of this proposal also meet the objectives for Public Engagement with Research by:
(i) Engaging effectively with the public
SHS is the only UK academic environmental scientist to have visited Fukushima twice (requiring special permission from Government and collaborative links with Fukushima University and JAEA). In 2011 SHS and LEM were invited to Fukushima to see first-hand the successful remediation of Fukushima University and the ongoing decontamination efforts at Namie-Machi (Futaba District, Fukushima Prefecture). In 2013 SHS also visited the Litate Villiage (Soma District, Fukushima Prefecture) as part of a field monitoring and sampling expedition. Researchers at Birmingham will use these experiences to engage with the public on how biological minerals produced during the 'BioLock' can be used to aid current decontaminations efforts. SHS set up a Twitter account @HandleySidhu and is actively posting about collaborative research in Japan (EPSRC funded Follow-on-Fund). She will continue to engage with the public in this manner during BioLock. AM and SHS will also apply to present BioLocks research at Birmingham's café scientifique (opening the research to the general public). LEM and PDRA Murray also have extensive experience with engaging with media and will work with the University of Birmingham's press office for dissemination of the high impact research expected from this grant.

(ii) Inspiring future generations of researchers in sciences by showing the relevance of NERC science to important social and environmental issues (iii) Building and sustaining a community of researchers active in public engagement.

Both SHS and AM are STEM ambassadors and will work with schools so that the future generation of researchers can make informed decisions about nuclear energy and better understand the issues of environmental radioactivity. Using photographs, film clips and comments (from public, academics and nuclear stakeholders) BioLock researchers will give a unique perspective on the remediation efforts in Japan and the impact of radiation vs. nuclear evacuation on the health and wellbeing of the community.

This project also offers a unique opportunity to work in overseas labs and interact with nuclear stakeholders in the UK (National Nuclear Laboratory, NNL) and Japan (Japanese Atomic Energy Authority, JAEA). The University of Birmingham currently has excellent links with Japan (JAEA, Universities of Fukushima, Hokkaido and Kyushu) which has been developed overtime and supported by grants (LEM headed a BBSRC Japan Partnering Award, Japan 'REIMIEI' award, £40,000). By working with Japan, the UK will gain new skills on contaminant remediation, maintaining UKs reputation in world class environmental research and feeding skills back into the UK (e.g. application of technologies to Sellafield sites).