Some ideas for NKS-B proposals

Project idea Bank to NKS-B, put together by Swedish Co-financiers

The Swedish Industry (NKS co-financiers) has created this list of their thoughts on tentative project proposals, which may serve for inspiration as ‘idea bank’ for further development amongst different actors, up to the NKS call for proposals. 

If you are interested in establishing a project on the basis of this, you are welcome to contact the Programme Coordinator (Kasper Andersson; kgan@dtu.dk), who may on your request establish a contact to relevant industrial organizations.  

IMPORTANT: NKS would by no means give priority or special treatment to project proposals submitted on the basis of this ‘idea bank’ - all submitted project proposals are evaluated according to standard procedures. 

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Assessment  of Fire Release Fractions (FRF)

Description

Waste from nuclear facilities is continuously generated during normal operations. It includes, for example, used ion exchange resins, evaporator concentrates, filters, etc. It is common practice to encapsulate the waste in concrete to immobilize the radioactive material, provide radiation shielding, and create manageable packages.

Safety analyzes of events in a waste facility often assumes a postulated fire breaking out in storage areas for radioactive operational waste. In these analyses, assumptions are made concerning release fractions of various radioisotopes or groups of chemical substances. The assumptions are based on data published by the International Atomic Energy Agency (IAEA) [1], and presented as so-called Fire Release Fractions (FRF). These data are intended to be generic but can sometimes be challenging to apply to the specific conditions being analyzed for waste facilities. It would be desirable to conduct a literature survey and perform experimental studies with the aim to produce complementary data on activity release during waste fires.

References

[1] IAEA Techdoc 1162, Generic procedures for assessment and response during a radiological emergency, IAEA 2000.

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Tentatively NKS-B “Measurement Strategy, Technology and Quality Assurance”

NPP Countroom Gamma Library

Collect gamma nuclide libraries from Nordic NPPs. Review them and make two comprehensive similar reference libraries for NPP countrooms that cover all nuclides needed. One library should be in Gammavision format and one in Genie format. All data should be from one single respected reference source (such as JEFF). Uncertainties should be included for all data (half-life, gamma yield etc) where possible. The purpose of the libraries is to allow a countroom to make a new library for the facility by starting out with the reference library and remove nuclides and energies that are unnecessary for the specific purpose of the library. Nothing should need to be added. Release the libraries along with a descriptive report. This would raise the data quality at Nordic NPPs in a very efficient way.

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Tentatively NKS-B “Measurement Strategy, Technology and Quality Assurance”

NPP Countroom Alpha Library

The same as the gamma project but for alpha.

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Tentatively NKS-B “Radiological and nuclear emergency preparedness”

NPP Severe Accident Library

Collect experiences on gamma spectrometry from severe nuclear accidents. Attempt to identify the nuclides and energies that are likely to appear in a gamma spectrum after a severe accident, in a fall-out sample or a sample from within the plant. Such spectra can be expected to be complicated. Make two similar libraries that cover the same range of nuclides and energies. One library should be in Gammavision format and one in Genie format. All data should be from one single respected reference source (such as JEFF). Uncertainties should be included for all data (half-life, gamma yield etc) where possible. The purpose is to provide a library for a decent "first try" at a gamma measurement on a fall-out sample. Release the libraries along with a descriptive report. A valuable addition would be if actual accident spectra could also be released along with the report, for training purposes, with the permission of the source facility or other relevant authority. For maximum convenience these spectra should be converted to at least Gammavision, Genie and simple channel-by-line formats.

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Tentatively NKS-B “Radiological and nuclear emergency preparedness”

Source Term estimation for emergency response at Nordic nuclear power plants

The overall goal of the project would be to investigate possible source term estimation methods for emergency preparedness and response organizations at Nordic nuclear power plants. The concept source term would include not only an estimation of amount of released nuclide-specific activity but also, and equally important, an estimation of the time period before a potential release might occur.

The project could include a comparison between already existing methods used in emergency preparedness organizations at nuclear power plants, discussing strengths and weaknesses with the various approaches. Specifically, the rationale for predicting potential source terms, including the time before release, for different scenarios (most likely, worst case) could be discussed.

Possible outcomes of the project:

Synthesis of existing methods to estimate the source terms in radiological emergencies.

Recommendations for future development of source term methods and tools.

A generalized method for estimation of source terms with rule-of-thumb guidance.

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Tentatively NKS-B “Radiological and nuclear emergency preparedness”

Prospective on-site dose rate assessments for potential exposures, caused by a radiological emergency at a Nordic nuclear power plant

The goal of the project would be to investigate feasible approaches for prospective on-site dose rate assessments for potential exposures after a radiological emergency, at Nordic nuclear power plants. The estimated dose rates would serve as a rationale for the dimensioning of emergency preparedness and response capabilities.

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Tentatively NKS-B ”Radioecology and environmental assessments”

Radiological baseline characterization study for new nuclear power plants in Nordic Countries

Investigate requirements for a pre-operational ‘baseline’ characterization study to establish radiation levels and activity concentrations in the environment around a new nuclear power plant in Nordic Countries. The baseline characterization should serve as an input to future radiological monitoring programs and prospective dose assessments for protection of the public and the environment.

Some issues of particular interest:

Specifics for a site where nuclear facilities are already in operation compared to new sites.

Specific challenges for Nordic countries.

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Tentatively NKS-B “Measurement Strategy, Technology and Quality Assurance”

Impact of the redefinition of operational quantities, on doserate measurements in nuclear facilities.

Short description of the project:
A detailed comparison of recently redefined operational quantities in the ICRU Report 95 (2020) to those previously defined by the ICRP/ICRU, for radiation fields that are of relevance for nuclear facilities.

Already existing data:

Comparisons of conversion coefficients from fluence to operational quantities (ratios of previously defined conversion coefficients to those proposed in ICRU Report 95) are presented in figures in chapter 4 in ICRU Report 95 for different energies of photons, neutrons and electrons.

Data that the project could produce:

Since the radiation fields at nuclear facilities can be a mixture of different particles with different energies it is of interest to analyze the corresponding ratios that are of relevance for nuclear facilities. The output of the work (a report including calculation data) could for example be used, together with known characteristics of the detector/instrument, to estimate the need for adjustments of personal dosimetry systems and area monitoring instruments.

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Tentatively NKS-B ”Radioecology and environmental assessments”

Assessment of impact to the environment of radionuclides released by nuclear power plants during normal operation – Nordic strategies and adaptation of tools

Short description of the project:

The aim of the project is twofold – to compile and compare the regulatory requirements and the strategies to meet those in Nordic countries concerning assessment of impact to the environment, and to assess and adapt the tools in use with regards to their suitability to the Nordic environment. The two parts of the project can be carried out independently.

Example of ongoing research in relevant area:

Ali, Yusuf: Accumulation of 63Ni, 106Ru and 125Sb in phytoplankton. Student essay, 2022. Sahlgrenska academy, University of Gothenburg, 2022.

Data the project could produce:

Template for a methodology suitable to Nordic conditions to assess the impact to the environment of radionuclides released by nuclear power plants during normal operation.

Recommendations on rationale for selecting representative organisms around a Nordic nuclear facility.

Syntheses of earlier radioecological studies of Nordic interest.

Data for modification of existing tools for assessing impact to the environment to reference ecosystems and reference species for Nordic environments (e.g. transfer functions, uptake functions, occupancy factors).

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Tentatively NKS-B “Measurement Strategy, Technology and Quality Assurance”

Investigations of C-14 in decommissioning waste from BWR and PWR

C-14 is an important nuclide in the context of repository storage and is found in decommissioning materials from various parts of nuclear reactors to a significant extent.

C-14 is produced by various nuclear reactions during normal operation in nuclear power plants. Most C-14 is either trapped in reactor water purification ion exchange resins or is released through the main stack effluents. Some C-14 is however incorporated into metal oxide layers in piping in the reactor (BWR and PWR) and turbine systems (BWR) and other materials in the off-gas systems.

During preparation before decommissioning the C-14 in primary reactor systems can be affected by chemical decontamination measures.

More knowledge is needed about how C-14 binds, for example, to the oxide layer on system surfaces and sand in delay tanks, both where in the oxide layer and the speciation of C-14 itself. Furthermore, it should be investigated whether there are differences between PWR and BWR and how chemical decontamination affects the C-14 content and speciation.

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Tentatively NKS-B “Measurement Strategy, Technology and Quality Assurance”

Investigation of the oxide layer in BWR/PWR and PHWR, related to decommissioning activities

The oxide layer on flow-wetted surfaces is the primary contamination carrier in non-activated decommissioning waste, i.e. piping and equipment outside of the reactor vessel. Moreover, the properties of the oxide layer determines the efficiency for various decontamination procedures. Recent international decontamination projects indicate difficulties in efficient decontamination for some materials and reactor types.

The differences in the oxide layer should be examined between various types of reactors, both before and after chemical decontamination. This includes the physical properties, hardness/appearance, etc., of the oxide layers, as well as their chemical composition. The aim is to gain knowledge and enable more efficient future decontamination procedures.

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