Description

Radioactivity is the spontaneous disintegration of an unstable atomic nucleus resulting in the emission of sub-atomic particles. Where a parent radionuclide decays to a daughter radionuclide so that the population of the daughter radionuclide increases this is known as ingrowth.

Relevance screening

Records the decision as to whether or not the FEP is relevant for consideration in the assessment. If not, a brief justification is given. If so, it is indicated to which compartments the FEP may a priori be relevant (near field, geosphere, biosphere, direct exposure).

NF/GEO/BIO/DE

NF consideration

Briefly records whether and in what way the FEP is considered in the near field part of the scenarios and models. These include the gradual release/leaching scenarios, i.e. the expected evolution, alternative evolutions and human intrusions in terms of effect on the containment capacity of the disposal system.

Long-lived progeny radionuclides are explicitly modelled

GEO consideration

Briefly records whether and in what way the FEP is considered in the geosphere (hydrogeology) assessment basis and models for leaching scenarios.

Irrelevant in view of the consideration of a non-radioactive solute flux (FEP 2.1.1) for establishing the GTF; Calculations for the spatial extent of contamination of the solid phase consider radionuclide-specific features (hence effects of decay (and sorption - see FEP 3.2.3))

BIO consideration

Briefly records whether and in what way the FEP is considered in the biosphere models associated with gradual release/leaching scenarios. In summary, a biosphere model is described for three biosphere receptors: a hypothetical well at the foot of the eastern tumulus, the river north of the site, and wetland zones between the disposal site and the rivers. The well yields the highest impact, and compliance with the equivalent skin dose limit needs to be demonstrated as well. The impact to non-human biota belonging to ecosystems associated with all three receptors is also assessed by means of an ERICA assessment.

Intermediate half-life progenies and radon are explicitly considered; short-lived and very short-lived progeny are assumed to be in secular equilibrium

DE consideration

Briefly records whether and in what way the FEP is considered in the direct exposure scenarios and models. These include human intrusion scenarios as used in impact calculations, human intrusion scenarios considered in performance analysis to assess the potential contribution of intrusion barriers, alternative evolutions in which direct exposure could occur (crater formation following a large passenger plane crash), penalising conditions beyond 2000 years.

Intermediate half-life progenies and radon are explicitly considered; short-lived and very short-lived progeny are assumed to be in secular equilibrium