ARMENIA PLANT SAFETY ASSESSMENT

An assessment of the technical status of unit 2 of the Armenia Nuclear Power Plant had been performed by a team of experts from FRAMATOME and Electricité de France in July 1991, at the request of the Armenian Government.

In their report the experts made observations on the general characteristics of the plant, which are common to all VVER 400 V 230 reactors of the same generation, and also on specific features of the plant which benefited from some safety improvements to take into account its location in a high seismicity area.

The report gave, in addition, 80 recommendations of actions or evaluations which, in the expert's opinion, should be undertaken if a decision to restart the plant would taken. These recommendations were ranked in two categories: priority 1 actions would have to be performed prior to the restart of the plant; priority 2 actions could be performed following the restart but should be completed within 2 or 3 years.

The main actions recommended can be summarized as follows:

• a verification of the plant's resistance to earthquake, and completion of the reinforcement works, so that safety can be ensured for an earthquake of intensity IX,
• works for restoring equipment and structures to their original state: vessel annealing, housekeeping of rooms and equipment; replacement of aged or obsolete equipment, reinstallation of removed or transferred equipment; treatment of the effluents and extension of the storage capacity for effluents,
• works for requalifying the safety functions to an operational state: complete inspection of pressure retaining components, and inspection of the steam generator tubes, functional requalification of the reactor protection system and of all safety related systems,
• improvements to remedy the main design inadequacies:
  • priority on actions to deal with reactor coolant system overpressure protection, steam line isolation, reactor protection systems, emergency electrical power supplies, fire protection, the safety injection system, the containment spray system, and assistance to the operator under post-accident conditions.
  • analyses to reassess plant behaviour in accident conditions and derive post-accident operating procedures,

finally, measures to improve the operating organisation: action plan for improved quality and safety; better definition of responsibilities; respect of procedures; improvements to operating and maintenance procedures; restoration of professionalism and motivation among the personnel; training,
It was also underlined that, in addition to the above-mentioned recommendations, it was also necessary to:

• maintain adequate relations with the technical bodies and institutes of the Russian ministry in charge of the nuclear industry,
• organize, at the level of the Republic of Armenia, adequate institutions in charge of the regulation and control of nuclear energy.

The work performed by FRAMATOME for the present project enabled more than fourteen experts to make an in-depth assessment of the condition of the Armenia Nuclear Power Plant. During the project, use was made of three technical evaluations of the ANPP, performed for non-Soviet organisations before the evaluations performed under this project:

• a seismic assessment by three specialists from Bechtel Power Corporation during the weeks following the December 7, 1988 earthquake,
• a safety assessment of Unit 2 by ten experts from FRAMATOME and Electricite de France during the summer of 1991, the results of which are briefly mentioned above, and
• a safety assessment of the ANPP by two representatives of the IAEA in May 1992 on a joint mission with the World Bank to study the energy situation in Armenia.

The project also made use of the generic assessment of the safety of VVER 440 V230 plants performed by IAEA (reported in IAEA - TECDOC-640): Ranking of safety issues for VVER-440 Model 230 nuclear power plants - February 1992. This study led to a classification into four classes of main generic issues, category III and IV being of highest safety concern.

The "Armenia Nuclear Power Plant Safety Assessment" project was proposed to the Commission of the European Communities by the Director of the Armenia Nuclear Power Plant (ANPP). It formed part of the TACIS 1991 programme of assistance to the Commonwealth of Independent States (CIS) in the field of nuclear safety.

FRAMATOME was chosen as consultant for the project, thus taking advantage of the knowledge of the Armenia NPP already gained by the company, particularly from missions performed in 1991 outside the framework of the TACIS Programme. The purpose of the project was to identify the improvements required to enable the Medzamor plant to be started up and run for a limited period and to define the tasks, lead times and costs involved.

For this five-month study, FRAMATOME created a basic team of twelve highly skilled engineers covering the following fields:

1. non-destructive testing,
2. earthquakes,
3. instrumentation and control,
4. maintenance operations (documents),
5. present documents evaluation,
6. procurement,
7. fire protection,
8. power supplies,
9. management and operating,
10. safety report and operating condition,
11. waste treatment.

Within the framework of the present contract, two missions have been conducted to the ANPP, the first with six experts from 7 to 21 October 1992, and the second with about ten experts including personnel from Electricité de France from 28 October to 4 November 1992.

They consisted of thorough inspections of the plant and of detailed interviews with members of the management staff and with plant personnel. They also allowed access to abundant informative technical documentation, although its use was naturally limited for those from the West, particularly due to the language barrier. The condition of the plant, the industrial environment and availability of local contractors were assessed.

The missions also gave an opportunity to form a first impression of the industrial environment and the problems of procurement of nuclear equipment from suppliers in the ex-USSR.
The objectives were to identify the actions required to:

• bring the ANPP up to the level of the same generation VVERs which are operating today in Bulgaria, in Russia, and in Slovakia;
• adapt the modifications undertaken on these VVERs following the IAEA recommendations;
• put into effect the specific measures made necessary by the seismic risk and the relative proximity of large towns.

The study was divided into four stages.

The first stage was necessary to assess the condition of the plant, both from the conceptual design standpoint and from the standpoint of the physical condition of the equipment and systems. The technical meetings and walk-downs at the Medzamor site made it possible to describe the type of work required.

The second stage, consisting of technical analysis of the required modifications, produced a description of all the work required to complete the studies and to execute the site works.
A third stage was also required which consisted in making industrial choices before drawing up the estimates and obtaining quantitative works data, such as volume of equipment, man-hours and completion time.

The final stage consisted in evaluating the overall cost and duration of the operation and generated the economic data to be used as the basis for renewed electricity production by the Armenia NPP.
On this basis, the Consultant drew up an action plan which would allow restarting the ANPP. An evaluation of the cost and duration of the work completed the analysis.

Despite the fact that the output of the project was the documented list of the improvements required to enable the Medzamor plant to be started up and run for a limited period, the experts were generally of the opinion that operation of the plant must be limited in time and must be halted as soon as replacement generating capacity comes into existence.