etudiant said:
Thinking carefully on an ongoing basis about options for when things go badly astray and implementing precautionary preparations such as you outlined, even if they are outside the Design Basis, seems to me normal good engineering practice. Not doing so and trusting to a Design Basis that may not reflect current knowledge clearly describes the Fukushima situation.
The industry does periodic assessments of Design Bases, especially after major events such as happened at Fukushima Daiichi. After TMI, considerable research was done an safety analysis methods. After Chernobyl, considerable research was done on assuring containment. The EU sponsored the shutting down of RBMK and VVER-440 units in E. Europe.
Here is one perspective on nuclear safety - Safety of Nuclear Power Reactors
http://www.world-nuclear.org/inform...-plants/safety-of-nuclear-power-reactors.aspx
However, the modest rate does not offset the impact on those in the vicinity of these accidents.
Following Chernobyl, International Nuclear Safety Advisory Group at the IAEA produced various reports on nuclear safety including the following report.
INSAG-8, A COMMON BASIS FOR JUDGING THE SAFETY OF NUCLEAR POWER PLANTS BUILT TO EARLIER STANDARDS, INTERNATIONAL ATOMIC ENERGY AGENCY, VIENNA, 1995
http://www-pub.iaea.org/MTCD/publications/PDF/Pub991e_web.pdf
1. INTRODUCTION
Safety requirements for nuclear power plants have not always been set consistently between plants and between countries. Although safety records and reliability data show that the majority of nuclear plants around the world are producing power safely and reliably, this claim cannot be made of all nuclear plants. For many reasons, including deficient design, inappropriate feedback of operating experience, ageing processes that have not been managed and absence of a programme of safety reassessment coupled with lack of appropriate safety assessment and verification by the regulatory authority, there are plants operating today with levels of safety that are inadequate in comparison with those of the majority of operating plants. This has led to a need for a common basis for judging whether the level of safety of a plant is acceptable.
2. HISTORICAL BACKGROUND
Concern about the need for a common basis for judging the safety of nuclear power plants came into sharp focus in die late 1980s and early 1990s as awareness grew of the inadequate levels of safety at some plants. In some cases the concerns focused on particular designs that safety experts were increasingly judging to be inadequate by current safety standards. In other cases, the concerns were focused less on a particular design and more on deficiencies in safety, such as poor operations, a weak safety culture or a weak national infrastructure for supporting safe operation of a plant. Also of concern was the recognition that some site related external events had not been adequately taken into consideration in plant design or in procedures at the plant.
These concerns were extensively discussed at the IAEA Conference on The Safety of Nuclear Power: Strategy for the Future, held in Vienna, 2-6 September 1991.
5. RESPONSIBILITIES:
The ultimate responsibility for the safety of a nuclear power plant rests with the operating organization. This responsibility is in no way diminished by the separate activities and responsibilities of designers, suppliers, constructors and regulators. The operating organization is responsible for all aspects of operation, maintenance, training, documentation and related activities. If deficiencies in design, construction or operation are identified, the operating organization should take appropriate corrective action.The current situation in the US after Fukushima can be found here.
https://www.nrc.gov/reactors/operating/ops-experience/japan-dashboard/emergency-procedures.html
https://www.nrc.gov/reactors/operating/ops-experience/japan-dashboard.html
http://www.world-nuclear.org/inform...ety-of-plants/three-mile-island-accident.aspx
The operators were unable to diagnose or respond properly to the unplanned automatic shutdown of the reactor. Deficient control room instrumentation and inadequate emergency response training proved to be root causes of the accident.
In addition to the US NRC, the federal regulator, the industry has INPO, Institute of Nuclear Power Operations, which was formed in 1979 in response to TMI.
http://www.inpo.info/AboutUs.htm
Evaluations
INPO evaluation teams travel to nuclear electric generating facilities to observe operations, analyze processes, observe plant activities, and ask a lot of questions.
With an intense focus on safety and reliability, our evaluation teams assess the following:
- knowledge and performance of plant personnel
- condition of systems and equipment
- quality of programs and procedures
- effectiveness of plant management
Additionally, INPO conducts corporate evaluations that are also focused on safety and reliability.
INPO can issue findings that can impact the corporate insurance rates, so utilities have a strong incentive to get it right.
