The STERPS (Source Term Indicator Based on Plant Status) project was intended to improve
the efficacy and coherence of off-site emergency management in Europe, including enhanced
decision support tools, development of better methods for predicting releases to the environment
based on the plant status and for data / information exchange. The Project was concerned with the
development of a decision support tool for emergency response by providing a capability for timely
estimate of the likely release of radioactivity to the environment from possible nuclear accidents.
This estimate is based on the status of the plant and takes account of the way in which the plant
is likely to behave, either passively or as a result of operator actions. The STERPS model is based
on the premise that information on NPP plant status can be deduced from key plant observations using
a probabilistic based model.
A generic system entitled SPRINT (System for the Probabilistic Inference of NPP Transients) has been
developed for source term forecasting using the Belief Networks (BBNs) method. Adaptation of SPRINT
has been carried out for a number of plants of Westinghouse, KWU and VVER design. These systems are
currently based on manual input of plant observations and judgments by an operator or analyst, from
which a corresponding plant state is deduced by inference in the BBN. Conditional probabilities in
the BBN embody expert judgment about the likely plant state corresponding to these observations.
Source terms are mapped to each final plant state based on existing calculations performed in the
plant-specific Level-2 Probabilistic Safety Assessments (PSA). The SPRINT is very much focussed on
providing direct support to the Decision Support System
RODOS, for use in off-site emergency management.
One important aspect of the STERPS programme was to demonstrate the practicality of interfacing a
BBN model for plant state diagnosis to a fast running (on-line) deterministic tool for real time
accident progression analysis and source term prediction. This more dynamic approach has potential
benefits but is technically more complex. A prototype tool has been developed based on the linking
of a specific BBN approach (mimicing the event tree from a level 2 PSA) to the existing ADAM
(Accident Diagnostics and Management) system. This approach has been named SABINE (Source Term Assessment by Belief Network).
The STERPS tool was developed within EU’s 5th Framework Programme by a project team from eigth organisations.
ENCONET Consulting was one of the organisations participating in the STERPS project. ENCONET Consulting possesses
all necessary expertise to support the user installation of STERPS and its linking with
RODOS equiped emergency centres.
In 2004-2005 the STERPS approach with its associated software tool SPRINT was tested in a simulated
operational environment. The related SPRINT demonstration project (CAT2DEM01) which is part of the
EURANOS Integrated Project within the European Commission sponsored
Euratom 6th Framework Programme was conducted with active participation of emergency response organisations
from six countries and co-ordinated by ENCONET Consulting.
