As the actual progress of the design, we purchase it according the batch. There are some problems existing in the co ntract management, such as more design changes, This paper mainly introduces the characters of BOP valve in CPR1000 nuclear power plant, analyzes the difficulty points of co ntract management, and explores its improving methods.
【Key words】 BOP valve; CPR1000; contract management 【Keywords】 BOP valve; CPR1000; co ntract management
【CLC】 TP311 【Document code】 A 【Article code】 1673-1069 (2017) 04-0138-02
1 Introduction The CPR1000 nuclear power plant technology originated in France. Taking the Daya Bay and Ling'ao Phase I nuclear power stations in Shenzhen as reference power stations, a great deal of experience has been learned from the construction of the project and corresponding technical improvements have been made [1]. The BOP (Balance Of Plant) system of nuclear power plants refers to power station auxiliary systems except nuclear island and conventional island. BOP valves are mainly used for power station auxiliary facilities such as integrated pipe galleries, thermal mechanic workshops and warehouses, combined pumping stations and desalination plants . Procurement of many types of valves , valves commonly used stop valve , ball valve , butterfly valve , gate valve . BOP valve contract using unit price contract, issued in batches more orders to the supplier procurement. The implementation of the contract faced many orders issued batches, valve specifications and more models without concentration. Due to the valve arrival requirements and project installation schedule to match, so delivery frequency requirements are high.
2 difficulties in the implementation of contract management 2.1 valve involved in the system More BOP valves involving plant systems up to 40 nuclear power plant in the main plant distribution shown in Figure 1. Because the plant construction and installation of valves of different time, so the valve arrival time needs to be divided into multiple batches. One type of valve may be used in more than a dozen plants, the first plant's valve installation time and the last plant's valve installation time difference of about 2 years. In addition, during the construction design institute will be based on the actual situation of the pipeline equipment transformation, increase and change the valve parameters. All of these increase the uncertainty of the final purchase type of BOP valve. Although the BOP valve procurement contract for the contract price contract, the tender also contains as many types of valves and specifications as possible, but because the actual procurement of valve types and quantities to the final design of the final date, so the valve parameters change the number of difficult to control. Due to the uncertainty of the type and quantity of valves to be procured in the future, valve suppliers are not readily stocked. Sometimes for a stove casting, to wait a few months.
2.2 Types of valves Multi-CPR1000 nuclear power plant 2 units BOP valve procurement type distribution shown in Figure 2. Among them, about 60% of the shut-off valves, about 70 kinds of specifications and models, the number of about 2000 units, is divided into 80 batches of orders, which lasted four years. Ball valve accounts for about 15%, the ball valve specifications about 50 species, the number of about 1000 units, other butterfly valves, gate valves, although the proportion of the proportion of small, but the specifications are still as many as a dozen, resulting in frequent and frequent purchase orders long. Often need to change the site installation time, the corresponding change in plant scheduling plans to improve the arrival of the valve and the on-site installation needs of the match.
2.3 to take measures 2.3.1 establish valve information ledger ACCESS database, each batch of design and publication of the BOP valve procurement list of the parameters are entered into the valve information account. Before entering the information, be sure to check the valve position code and the previous purchase order is repeated, and the valve function code as the only index in the valve query, because the site installation diagram also shows the specific valve function code. Installation department need to check the valve delivery, you can quickly find the valve from the account of the design parameters of the valve, the actual valve to the box and other important information, but also the SAP system inquiries outside of another fast information query. Project contract Document data management is an important part of engineering contract management. Good management can improve the performance of contract performance and provide credible evidence for solving contract disputes and claims [12].
2.3.2 Establish Good Communication Although the new CPR1000 nuclear power plants are designed with reference to the completed nuclear power plants, it does not mean that the new nuclear power plants simply copy the equipment list of old nuclear power plants. BOP valves are widely selective in design and different design institutes choose different types of valves to achieve the same function. In addition, due to different projects of nuclear power plant operators, will require a different transformation, the Institute is also difficult to predict in advance.
In view of the above, communication with the field installation department is particularly important. Otherwise there may be a lot of arrival of the valve, but the installation time did not arrive, resulting in a long time valve storage. In addition, the construction site of each plant construction and installation of a great gap between the time, the largest difference of more than 1 year. Therefore, the installation department feedback valve demand time is very important, at least once a week with the scene to communicate the needs of the valve. On-site urgent needs of the rolling plan (1 month to install early warning), need to actively supervise and coordinate suppliers to take all measures to ensure that the valve supply, if necessary, the contract executive will be in charge of plant coordination to verify the valve actual production progress. To ensure the valve according to the on-demand supply, the contract is the primary goal of the implementation.
2.3.3 Creating a Valve Buffer Due to the uncertainty of the publication time of a valve's purchase list, there are often some valves that are in dire need of emergency. Some of the nominal diameter of the valve is small (DN15, DN20, DN25), low prices, less cost. Therefore, the Hongyanhe project site set up a BOP valve buffer library, provided by the Design Institute buffer valve technical parameters, and then place an order to the supplier scheduling. Project construction site according to follow-up design and publication of the valve list, giving priority to using the same type of buffer tank valve, the equivalent of stock. But at the same time, there are some risks. If these valves are not designed in the future, it will cause pressure on the stock. Buffer valve to the scene after the scene, the need to strictly manage the use of inventory, if you do not make a special dedicated, you can not play its original role. How to make the investment into the construction of the project so that limited funds can be rationally and effectively distributed so that the construction projects in the most economical way to get the maximum economic and social benefits [2,3], which is the establishment of the valve buffer must be the key consideration problem.
3 Conclusion Nuclear power plant project on the BOP valve demand, time is tight, many uncertainties. The timely and accurate management of information process in contract execution can find the problem faster and more effectively, which provides a good foundation for promptly solving the valve technical problems encountered. And the design institute and on-site construction and installation department to establish a good and smooth communication channels, greatly improving the arrival of the valve and the actual installation of the match. The establishment of a valve buffer library, effectively solve the part of the emergency valve needs, so do with the use. BOP valve contract management involves the implementation of multi-sectoral communication and collaboration, so need to work closely with more departments, but also the strong support of suppliers to ensure that all construction projects in an orderly manner to complete the installation. The current design of BOP valves has led to the inability of BOP valve contract management to extricate from the complex exchange of information, tracking and feedback.
【references】
[1] CPR1000 Brief Introduction to China's Improved PWR Nuclear Power Plant [J] .New Power, 006 (05): 36-38.
[2] Lu Fengdi. Bidding and contract management in practice [D]. Hefei: Hefei University of Technology, 2010.
[3] XU Li, WEI Yunwu, NI Shousheng. Design Management in EPC Project [J]. Architecture Design Management, 2010 (01): 11-13.
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