Expected impacts

As a first-of-a-kind project addressing Management and Uncertainties of Severe Accident analysis involving industry leading organizations in a multinational context, any impact of the project will have a substantial dissemination. In fact, as a result of MUSA, a sound and broad experience bank is achieved concerning all aspects of the project. In particular, MUSA contributes to four expected impacts within the work programme:

1. To close-out open issues in the severe accident area. MUSA characterises the uncertainties in SAs analyses, including some SAM actions. By doing so, in particular the uncertainties governing the ST estimates are identified so that future research can be better focused to reduce ST predictions uncertainties.

2. To support assessments and improvement of NPPs’ safety based on results of simulation codes, use of experimental data and estimate of risks to increase safety margins of power plants under operation. The support to NPP assessments is inherent in the MUSA project. The uncertainties involved in any SA analyses make it meaningless to describe any accident evolution as a single value at-time profile and the transition to the more realistic “band profile” description should be preceded by a specific study on how to bring the UQ methodologies to the arena of SA analysis. This is even more pertinent when SAM measures are also included in such analyses. The key consequence of this new approach is the more accurate and reliable determination of safety margins, in which questionable approaches in SAs, like conservatism, may be abandoned.

It is also worth noting that MUSA uses data to test the application of existing and innovative UQ methodologies in the SA domain. It is highly likely that some of these data resulted from previous EC supported projects, like PHEBUS, SARNET, PASSAM and others. Namely, MUSA also contributes to a better exploitation of previous investments made under the EC EURATOM frameworks.

3. To enhance emergency response measures and SAM strategies, through result-based recommendations. MUSA provides more realistic descriptions of SA footprints, particularly of the STs to the external environment, both in the case of reactors and SFPs, with and without inclusion of SAM actions. This means that a more sound assessment of some mitigation actions might shed some light on how and when to better implement them. Additionally, a more realistic and reliable ST would eventually translate to a better definition of emergency actions, both in terms of timing and the specific form of implementation.

4. Furthermore, this action is to draw on the unique EU expertise in order to enhance nuclear safety whilst also boosting the EU safety requirements’ implementation. The MUSA project draws on the sound expertise built within EU and beyond. The broad external participation, from North America to Asia, provides a good basis for propagation and harmonisation of EU safety requirements and their implementation, in addition to fostering knowledge and knowhow sharing. Besides, the diverse nature of organisations involved (universities, research centre, technical support organisation, industry and regulatory bodies) create a sound network in the investigation and in the shearing of aspects of nuclear safety in which all entities are involved.