3. Lessons learned and improvements

A number of lessons can be drawn from these four historical accidents.

• Weaknesses in the design of these facilities make them appear vulnerable:

  • At Kyshtym, the storage facility and its instrumentation are not suitable for high-level waste;

  • At Windscale, the reactor was designed very quickly, without giving much thought to the problem of the Wigner effect in the graphite stack; moreover, more demanding operating conditions (presence of enriched uranium cartridges) had not been anticipated;

  • at TMI-2, inadequate instrumentation misled the operators; in addition, the large quantities of information arriving in the control room, which were not prioritized or adapted to the conditions of the accident, made...