[en] The present paper deals with the Incomplete Rod Insertion (IRI) problems experienced at the Belgian nuclear power plants (NPPs) of Doel-Unit 4 and Tihange-Unit 3 and presents the various remedial action taken to try to address the cause of such abnormal situations. A chronological description is made of the major events that developed at both units since the IRI problem was detected, i.e. since June '96 at Doel 4 and since October '96 at Tihange 3. The problems that arose from IRI are discussed as well as the position adopted by the Belgian Safety Authorities (BSA) and the action taken by the plant operator, his engineer and by the fuel suppliers. Also described are the consequences on how fuel supply and operation cycles of both units are managed. (authors)

[en] After a brief introduction the article reviews the general starting and its organization, the chronology of the commissioning, the starting schedule as well as the first data concerning the operation experience of the Tihange-3 reactor. (AF)

No abstract available

[en] The signal transmission system PROCONTROL P was developed by BBC to increase reliability and availability in power plants and to reduce cable costs. This system, which also satisfies the security requirements of nuclear power stations, ensures high flexibility during commissioning as well as for future extensions or modernization. The article describes some potential applications of the system by referring to three power plants in which it has been installed. (Auth.)

[en] With a few inexpensive modifications to the control systems and procedures, Westinghouse has improved the operational flexibility of its plants during load following and operational transients. The Westinghouse improved load follow package (ILFP) consists of: a lighter bank of lead control rods; a widened operational flux difference band; and the use of a reduced primary coolant temperature during fast increases in power. Demanding tests at Doel-4 and Tihange-3 have confirmed the expected increase in performance throughout the in-core fuel cycle. (U.K.)

[en] Leak-Before-Break (LBB) technology has not been applied in the first design of the seven Pressurized Water Reactors the Belgian utility is currently operating. The design basis of these plants required to consider the dynamic effects associated with the ruptures to be postulated in the high energy piping. The application of the LBB technology to the existing plants has been recently approved by the Belgian Safety Authorities but with a limitation to the primary coolant loop. LBB analysis has been initiated for the Doel 3 and Tihange 2 plants to allow the withdrawal of some of the reactor coolant pump snubbers at both plants and not reinstall some of the restraints after steam generator replacement at Doel 3. LBB analysis was also found beneficial to demonstrate the acceptability of the primary components and piping to the new conditions resulting from power uprating and stretch-out operation. LBB analysis has been subsequently performed on the primary coolant loop of the Tihange I plant and is currently being performed for the Doel 4 plant. Application of the LBB to the primary coolant loop is based in Belgium on the U.S. Nuclear Regulatory Commission requirements. However the Belgian Safety Authorities required some additional analyses and put some restrictions on the benefits of the LBB analysis to maintain the global safety of the plant at a sufficient level. This paper develops the main steps of the safety evaluation performed by the Belgian Safety Authorities for accepting the application of the LBB technology to existing plants and summarizes the requirements asked for in addition to the U.S. Nuclear Regulatory Commission rules

[en] Framatome has delivered three new steam generators to the 1020 MWe third unit of the Tihange nuclear power plant in Belgium, only 32 months after receipt of the order; these SGs are exceptionally large (22.5 m long) and are equipped with 6019 U-tubes. The Chalon-St Marcel factory has designed and manufactured 425 heavy nuclear components, 76 reactor vessels, 281 SGs and 68 pressurizers

[en] The full scope simulator, a replica of the Tihange 2 power plant is located at the Tihange nuclear training center (CFN) on the site of the three Tihange power plants. The scope of simulation was initially extended by adding a specific feature of the Tihange 3 plant (the bunker system), but there was also a need to implement specific features of the Tihange 1 unit for operator training, such as: very high pressure safety injection; residual heat removal system; reactor protection logic. The corresponding models of Tihange 2 can be replaced by equivalent software models for Tihange 1. When operated in the Tihange 1 mode, the dedicated hardware panels of the Tihange 2 control room, are replaced by so-called soft panels implemented by software emulation in a full size and full function display. The advantages and disadvantages of such a solution from a technical, economic and pedagogical point of view are discussed in the presentation, and also the methods how this technique can be extended to the development of multi-function simulators are outlined. (2 figs.)

[en] More than 60% of the electrical power of Belgium is generated by 7 PWR nuclear power plants. For 3 of them seismic adequacy of electro-mechanical equipment had to be reassessed due to increased seismic requirements. Design stage for these plants extended from the late sixties to the early eighties. The problem is similar for many US plants. These utilities, along with several European utilities, among which the Belgian, formed a group Seismic Qualification Utility Group (SQUG)to solve the problem. The procedures developed by SQUG were adapted to the specific Belgian situation. Main concerns were the applicability of the US data base to the Belgian equipment, the training program for the walkdown team and the specific requirements of the Belgian Safety Authorities concerning the equipment needed to reach safe shutdown conditions. Very few serious problems were found in the older units. Some minor problems were found in the newer ones. The experience from this walkdown confirms that this approach is very cost effective. (author)

[en] In our democratic countries, fair acceptance by the public of the various stages in the implementation of a nuclear programme is a condition sine qua non for its success. In this respect, the public opinion of the local community always plays a major role and could become crucial in particular circumstances when, for instance, a new site is created or an accident occurs. Therefore, local information should be given priority and be perceived as a key factor in any communication strategy. However, mere information is not enough. Information is like grain it can only germinate in a well prepared soil. In other words, the fair and positive perception of any information or message relies not only on its quality but equally on the credibility of the source (utility, nuclear lobby, etc... and the reservoir of goodwill It has been able to create within society. The purpose of this paper is to relate the successful actions observed at Tihange N.P.P. This plant is located near the town of Huy along the river Meuse in Southern Belgium. Its total capacity amounts to 2,790 MW. The three PWR were commissioned respectively in 1975, 1983 and 1985. There is good evidence to believe that the Tihange nuclear power plant is presently well integrated in its socioeconomic environment. The plant's management lives in a climate of positive 'peaceful coexistence' with the local authorities, the last demonstration against the plant dates back to some 10 years ago and very little criticism, if any, is heard from the local community. Possibly the most convincing evidence of this relaxed atmosphere is that none of the candidates put forward by environmentalist parties were elected in the latest general and municipal elections at Huy. Dual policy aimed to promoting congenial neighbourly behaviour and giving priority to local information has undoubtedly significantly contributed to this result