The NEA Committee on the Safety of Nuclear Installations (CSNI) Working Group on Risk Assessment (WGRISK) will hold an international workshop on Level 2 PSA and Severe Accident Management in Cologne, Germany on 29-31 March 2004. The workshop will be hosted by Gesellschaft für Reaktorsicherheit (GRS) mbH.
The workshop is open to experts from regulatory authorities, research organisations, utility and industry representatives and observers from both OECD member countries and non-member countries. Nominations should be made through the NEA Secretariat or CSNI/WGRISK members. Those wishing to make a presentation at the workshop should submit an abstract with their preliminary registration.
To provide a forum to discuss recent developments in Level 2 PSA and Severe Accident Management. The information gathered will be used to produce an addendum to the 1997 WGRISK report, and will provide input into the joint workshop planned by WGAMA, IAGE and WGRISK on the Evaluation of Uncertainties in relation to Severe Accident and Level 2 Probabilistic Safety Analysis (to be held in the autumn of 2004).
Level 2 PSA definition: A Level 2
PSA identifies the ways in which radioactive releases from the plant
can occur following core damage and estimates their magnitudes and frequency.
This analysis provides additional insights into the relative importance
of the accident prevention and mitigation measures such as the reactor
Level 2 PSA state of the art: WGRISK
produced a state-of-the-art report on Level 2 PSA Methodology and Severe
Accident Management in 1997. At the 2000 WGRISK meeting, it was reported
that a review into results from the last 10 years of severe accident
research has revealed that approximately 50 to 100 million USD has been
spent but little information exists in published literature as to how
this research has affected Level 2 PSAs.
The modern standard is now to carry out Level 2 PSAs for nuclear power plants, which provides information on the source terms and frequencies for the accident sequences that could happen following core damage. This information could be used as the basis for formulating the off-site emergency plans for the site.
At the last meeting of WGRISK in November 2002, members discussed the
current state of the art for Level 2 PSAs and what, if any, actions
were needed by the group in this area. Reports were given on two recently
completed reviews of the 1997 report. The results were similar in that
the sections on Level 2 PSA and severe accident management were still
current and that many of the new Level 2 PSAs being performed are following
the approaches stated in the existing report. However, it also noted
several important points as follows:
Based on these results, the CSNI agreed that the WGRISK should organise a workshop to collect new information (as described above) and that the results should be used to produce an addendum to the 1997 report.
NOTE: Copies of the 1997 report [NEA/CSNI/R(1997)11]
are available on the NEA website. Hard copies of the report and additional
references may be obtained through a request to the Secretariat.
Level 2 PSA Methodology
and Severe Accident Management [NEA/CSNI/R(1997)11]
Prepared by the CNRA Working Group on Inspection Practices (WGIP)
© 2004 Organisation for Economic Co-operation and Development
Last updated: 27 April 2004