Production and supply of new anchor sets for containment pre-stressing system of Unit 6

Project: „Production and supply of new anchor sets for containment pre-stressing system of Unit 6”
Client: „NPP – Kozloduy“
Contract: № 178014/28.12.2007
Execution: 12. 2007÷05.2008
Description: Manufacture and supply of kits for anchors of building structures under tension, required to replace existing ones in units 5 and 6 of Kozloduy NPP. The company’s specialists perform analysis to determine the suitable material and recommended the heat treatment process, which is consistent with the necessary mechanical characteristics for the final products.

1. Preparation of technical documentation for the supply of anchors SPNZCH block 6

The task consists of two parts:

  • Part 1 contains the developed technical documentation – selection and justification of a particular brand for the production of steel anchor bolts and nuts, preparation of drawings of the anchor bolt and nut, which requested from the NPP “Kozloduy” products to be made. In the drawings are given the exact dimensions and tolerances relevant fields as applicable to the case and GOST and BDS standards . Strictly prescribed range and the necessary firmness throughout the volume of products.
  • Part 2 contains a detailed program to conduct factory monitoring and control of incoming anchor units – anchor bolts and anchor nuts. Have been prescribed performance requirements of the factory of thermal curves for the entire process of thermal treatment of products. In essence, this is one of the highlights in this task to ensure the necessary mechanical strength and hardness throughout the volume of products.

2.Manufacture, supply and installation of new anchor kits SPNZCH 6 of Kozloduy NPP aimed to prepare the required number of products, as prescribed by the CA requirements. The products are made in a factory with proven experience in the production of this type of products. By ATP Atomtoploproekt Ltd. conducted a thorough control of the manufacturing process to achieve the prescribed requirements to the devices.At most it applies to comply with precise geometric dimensions, tolerances flight technology of heat treatment and the required hardness in specific areas. Destructive testing was conducted on samples of anchor screws and nuts for practicing the heat treatment in order to reach the necessary blow toughness throughout the volume of products and consequently achieve hardness in strictly defined and prescribed by us range for trouble-free operation of these products. Supplied products successfully passed the full input volume control in Kozloduy NPP and were installed without problems to SPNZCH block 6.