There have probable been no such complex and attracting strong global attention project in the world history of NPP construction yet, as completion and start-up by Russian experts of Bushehr NPP in Iran. This project can surely be brought into line with creation of the first in the world NPP in the city of Obninsk. The same unique and enormous complex of engineering tasks has been solved in the Iranian project as at the first NPP, and successful start-up of the plant was not less important from the political point of view.
Teheran gave thought to its first NPP in the early 1970s. The state Iranian delegation headed by Mohammad Reza Pehlavi, the Shahinshah of Iran, visited the Soviet Union (which was at that time the world leader in construction and operation of nuclear power plants) in 1973. Visitors saw over Novovoronezh NPP, familiarized with the Soviet experience of nuclear power units construction and discussed the possibility of signing a contract on NPP construction with water-cooled power reactor in Iran. It is to be recalled that units of Beloyarsk and Novovoronezh NPPs were operating at that time in the USSR besides the nuclear power plant in Obninsk; two units with VVER-440 reactors were operating in Novovoronezh NPP. But in the end rather for economic reasons (it seemed to them to be cheaper) Teheran chose the project of German Kraftwerk Union AG (KWU) company for its NPP (this company was created in 1969 by Siemens and AEG companies).
By 1980 the first power unit construction works were performed almost by 90%. But Islamic revolution of 1979 terminated all works. Western countries imposed embargo on delivery of nuclear technologies to the Islamic Republic and KWU company left Iran. But in 1992 the Islamic Republic Iran addresses our country again with the request to assist in nuclear engineering development. Moscow and Teheran signed on August 24, 1992 the cooperation agreement in the field of peaceful use of nuclear energy, and on August 25 they signed the cooperation agreement in the field of NPP construction in Iran. Preparation to sign the contract on construction of two VVER-440 power units within these agreements has begun the same year. At the same time the Atomic Energy Organization of Iran suggested that Russian partners consider the possibility to complete the first power unit of Bushehr NPP. During the preparatory period on the plant site the Russian experts inspected the reactor department, building structures of the main building and other buildings and facilities, installed equipment and the performed installation works. Several thousand units of equipment, armature and pipe spools were examined. Simultaneously with inspection of already installed systems the Russian experts analyzed the equipment located in storage facilities. Iranians, of course, did not have the complete inventory of equipment left by the Germans, and our nuclear scientists in fact tried to come around every corner and storage facilities of Bushehr NPP site. Iranians preserved the unit and equipment very well, they handled and stored the equipment very carefully on the site. Everything that was left, was stored in storage facilities. The found equipment was delivered to workshops, unpacked, examined, preserved again and delivered back to storage facilities. Inspection was in-depth and diversified so that documentation and experience of a similar analysis became highly sought to perform similar works at domestic and foreign nuclear power plants, where construction was suspended and where the decision was made to resume works on commissioning of these NPPs. The contract on completion of construction of the first unit of Bushehr NPP was signed in January, 1995. According to the 1995 contract the Iranian colleagues has a number of obligations, a considerable part of works, including completion of the second category buildings (supplementary buildings). The customer did not manage to fulfill its obligations and took the contract on a turn-key basis. In 1998 partners signed the addendum to the 1995 contract, according to which Atomstroyexport completes the construction of the first unit on a turnkey basis with the installed electric capacity of 1000 MW with В-446 reactor facility. Why did actually Russia undertake the obviously most complicated, unique task of construction of a modern nuclear plant for Iran? The answer to this question is simple — during this period of time there was a question of survival of our nuclear industry, the constructors needed a large order that would allow preserving the personnel, updating the experience and with some luck become recognized in the world market of commercial reactor engineering. Vladimir Pavlov, vice-president responsible for projects in the Near East and Central Asia the of the Incorporated Company JSC NIAEP — JSC Atomstroyexport, which is the immediate supervisor of the construction project completion of the first Iranian NPP, believes that this contract was extremely necessary for Russia to preserve the current construction potential of the industry. Iranians made a severe condition to the general construction contractor — JSC Atomstroyexport — to use in the project the German equipment delivered to Bushehr site back in the 1970s, which was stored under lock and key for many decades. Teheran thought at that time that a similar “know-how” would essentially decrease the project costs. Besides that, equipment appeared to be practically new and did not cause any concerns of the customer in terms of reliability. Today the customer recognizes that it would be more efficient and cheaper to construct the power unit «from scratch», but at the time nobody even suspected the enormous amount of works required. The main problem was that no company in the world had the in-depth integration experience of technologies of absolutely different countries in terms of the NPP project, which, moreover, were distanced from each other by decades. Integration of Russian and German technologies demanded to combine approaches of the two nuclear engineering schools, resolve the difficulties with different regulatory bases and design norms, lead to a single quality evaluation criteria. KWU project was developed based on the old German normative documentation, while the Russian project was created based on the modern Russian normative documentation. Association of results of integration with the project of the referential unit led to numerous collisions.
Countdown of Bushehr NPP construction by the Russian party started in 1998. Delivery of the basic process equipment to the NPP has begun in 2001. From the very beginning of works, Iranians had no information on the number of integrated German systems and machines. A decision was made, not waiting for the raw data on equipment available at the site, to implement the project using similar Russian equipment. Certainly, due to this work, it became possible to put the works into motion, but later, when the real equipment was delivered to the power unit, the original project was subjected to a great many modifications. There were absolutely unexpected problems that were solved on the move. For example, it was originally considered that Germans erected buildings strictly according to their construction plans, but it appeared that during installation they changed a lot, while this imposed other requirements both to contractors and to manufacturers of systems and machines. As the result, Bushehr NPP has very many variations from the referential power units of domestic nuclear power plants. But at the same time it is worthwhile noting that there are all necessary systems to maintain safe operation at the first Iranian nuclear power plant, which are used at Russian NPPs referential to the Iranian project.
In the beginning of works at the site it seemed to Russian experts that it was possible to successfully use all equipment located in storage facilities. But very soon it became clear that the difficulties are insuperable for many systems.
«For example, we had already mounted German diesel generators there, and these were in excellent condition. These generators are one of the basic elements of the plant safety, they shall operate in case of external blackout of the plant. But the German equipment even had no documentation and passports. And then the decision was made to refuse using this equipment, because this equipment did not comply with the second class of safety», — recalls Pavlov.
This decision was made in 2000 and then it appeared to be the only correct decision. As the result, Russian diesel generators were delivered to the Iranian plant. Today, after almost 1217 years the domestic experts say that they accumulated such a serious experience of integrating foreign systems, that they would effortlessly use it in any projects. The events were being interestingly developed involving the other complex — German refrigerators, which also were found out in the storage facility.
Huge refrigerating systems are provided according to the NPP geographical position, hot and damp climate at the plant.
One of them, the system of cold water intermediate circuit, is intended to provide the coolant to the air cooling units of unit premises, plant buildings and facilities, process equipment. Heat produced by the refrigerating units is withdrawn to the intermediate circuit system of non-urgent customers for the cold water central plant, then to the system of cooling water of non-urgent customers of the turbine building and further to the Persian Gulf. Three freon refrigerating units were installed in the system, with the refrigeration capacity of each of them making 17.4 MW.
But operation of German refrigerating systems “SULZER” found in a storage facility was refused originally due to the absence of documentation. Atomstroyexport reckoned upon deliveries of similar equipment from the third countries, including South Korea. Unfortunately, international sanctions regarding Iran led to that all potential partners refused to participate in the project. As the result, Russian experts came to a conclusion that the available refrigerating systems may all the same be integrated in reasonable terms and with reasonable costs at Bushehr NPP according to the second class of safety. This was successfully performed in 2008.
“Situations concerning diesel generators and refrigerators are the demonstration of our engineering thought at Bushehr NPP site. Over eight years, starting from 2000 to 2008, we have learnt to do the most complicated things, in particular, to apply equipment in the project with unavailable documentation. We have reached in integration the necessary quality, which allowed us showing and proving the supervising body all necessary safety of nuclear power plant systems. In 2000 nobody even wanted to integrate German refrigerators, but we performed this work in 2008 and have therefore provided the start-up,” says V. Pavlov. Integration of refrigerating machines was performed by Atommashexport company.
Our constructors faced another surprise when it came to turbine installation. Originally the decision was made to use the foundation of a low-speed (1500 RPM) KWU turbine to integrate the building with the turbine department equipment. Low-speed turbine of Ukrainian OJSC Turboatom was located in the building constructed way back by Germans, since both German and Ukrainian turbines are shorter than Russian turbines. Unfortunately, Ukraine refused to deliver its turbine for the project under the pressure of the USA. Alteration of foundation for the standard turbine of Russian “Power machines” would lead to destruction of the building. Therefore it was necessary to solve a more challenging task on installing the high-speed turbine (3000 rpm) of the Leningrad metal factory on the existing KWU foundation. The domestic turbine turned out to be unique, existing in the single original, since it was simply manufactured with a shorter length. Experts worried about how it would show itself in work, since the typical Russian machine was essentially adjusted to the site requirements. It was especially important to understand the turbine vibration parameters. But as a result almost a miracle happened — the turbine start from rest had absolutely no vibration, i.e. it started at once. This is the best characteristic for those who created the unique machine, who installed it and was engaged in starting-up and adjustment works.
Many people did not believe that our nuclear scientists would manage to successfully complete the Iranian project. Each achievement at the construction site — for example, nuclear fuel delivery, completion of starting-up and adjustment works, loading of fuel element simulators, beginning of the power unit physical start-up, was perceived with a grain of salt by the experts, politicians, journalists in many countries. But Russia has stood to its promise — works on rising the nuclear steam generating system to its minimum controlled level of capacity were performed on May 8, 2011 in the power unit, and the power start-up of the first Iranian NPP took place on September 3, 2011. At the solemn ceremony held on September 12, 2011 dedicated to the Bushehr NPP hook up to the country power network, Sergey Vladilenovich Kirienko, the General Director of the State Atomic Energy Corporation “Rosatom”, reminded that Iran had waited for almost 30 years for the start-up of this plant.
