Severe accident management

Severe accident management the present state of studies and implementations... 

A Nuclear Energy Agency report (NEA, 1995) contains the summary and conclusions of an international specialist meeting on the implementations of severe accident management, in the framework of an OECD activity lasting many years on the subject of accident management. The document makes clear... 

The transfer of scientific knowledge on phenomena into actions and procedures is a difficult process (see the above quoted case of the pouring of water on a degraded core) research still plays an important part in the implementation of accident management. Moreover, additional work is needed in the field of severe accident management under low power or shutdown conditions. 

NEA (1995) Summary and conclusions. Report NEA/CSNI/ R(95)16 Specialist meeting on severe accident management implementation, Niantie CT, 12 14 June, Nuclear Energy Agency. 

The results of the VIP programme confirm the importance of proper severe accident management, as the presence of a small amount of water may be decisive. Also the avaUability of a voluntary depressurization of the primary system is essential, which removes the possibility of many possible scenarios of vessel rupture. The programme also confirmed the need to actively continue studies and research on the external cooling of the pressure vessel in case of severe accident. 

American Physical Society (1985) Radionuclide release from severe accident management implementation , Study group report. 

Figure 1. Severe accident management support system framework.

The severe accident management support system consists of four major modules as sub-systems (a) severe accident risk data base module (SARDB), (b) risk-informed severe accident risk data base management module (Rl-SARD), (c) severe accident management simulator module (SAMS), and (d) on-line severe accident management guidance module (On-line SAMG). The framework of the severe accident management support system is represented in Fig. 1. More detail concepts are described below. 

Severe Accident Management Simulator Module (SAMS)... 

The plant model used in this module is oriented to severe accident phenomena and thus can simulate the plant behavior for a severe accident. Therefore, the module may make an assistance role of the information source for decision-making for a severe accident management. 

On-line Severe Accident Management Guidance Module (On-line SAMG)... 

In Korea, the severe accident management guidance (SAMG) was developed (KAERI, 1998), and it is... 

KAERI, 1998. Development of Severe Accident Management Guidelines for Korean Standard Nuclear Power Plants. Korea Atomic Energy Research Institute,... 

OECD NUCLEAR ENERGY AGENCY, Level 2 PSA Methodology and Severe Accident Management, Rep. OECD/GD(97)198, OECD, Paris (1997). 

The ABV reactor is equipped with the low pressure boron injection system and reactor cavity flooding system. Both are non-automatic and non-safety graded systems and designed for severe accident management... 

INSIGHTS INTO THE CONTROL OF THE RELEASE OF IODINE, CESIUM, STRONTIUM AND OTHER FISSION PRODUCTS IN THE CONTAINMENT BY SEVERE ACCIDENT MANAGEMENT... 

The Task Group on Containment Aspects of Severe Accident Management (CAM) is a specialised extension of PWG4. Its main tasks are to exchange information, discuss results and programmes, write state-of-the-art reports, organise specialist workshops on containment accident management and on techniques to protect the containment and their implementation. 

In a second phase, members of PWG4 s task Group on Containment Aspects of Severe Accident Management (CAM) enriched the report with severe accident management considerations. These can be found at the end of Chapters III to VIII. 

The report does not aim at exhaustiveness, nor at direct applicability to severe accident management situations. Its aim is to give a picture of what is known in the area of fission product sources and how this knowledge can be put to use to mitigate them. Implementation has to be developed on a plant-by-plant basis, taking account of plant specifics. This is the task of the utilities. 

Reactor accidents that progress to the point that core debris penetrate the reactor vessel and cascades into the reactor containment are, of course, quite severe. At this stage in a severe accident, only the containment provides a barrier to the release of radioactive materials from the plant into the environment. Indeed, if decay heat removal from the contaimnent could not be realized in a sufficient way, the failure of this last barrier becomes inevitable. Severe accident management efforts must, then, focus on ... 

J.M. Ball, et Al., INTERNATIONAL STANDARD PROBLEM (ISP) NO. 41 Computer Code Exercise Based on a Radioiodine Test Facility (RTF) E5q)eriment on Iodine Behaviour in Containment under Severe Accident Conditions , In Proceedings of OECD Workshop on Iodine Aspects of Severe Accident Management, NEA/CSNI/R(99)7, Vantaa, Finland, 1999. 

L.E. Herranz and F. Robledo, A Potential Strategies to Control Iodine Released into the Containment in the Case of a Severe Reactor Accident , In the Proceedings of OECD Specialist Meeting on Selected Containment Severe Accident Management Strategies,... 

C-8. H. Tuomisto, et al, External spray cooling of the Loviisa containment . Proceedings of the Specialist Meeting on Selected Containment Severe Accident Management Strategies, CSNI Report NEA/CSN1/R(95)3, Committee on the Safety of Nuclear Installations, Paris, 1995. 

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