Introduction to AP1000 Nuclear Power Engineering Welding Document Review

1 Overview

AP1000 is a 1000MW pressurized water reactor nuclear power unit developed by Westinghouse. It belongs to the third generation of nuclear power technology. It adopts the concept of “non-active” design and utilizes the inherent thermal hydraulic characteristics to simplify the design of safety system and make the safety function of nuclear power plant not. Re-reliance on the operation of active equipment such as pumps and fans. Zhejiang Sanmen Nuclear Power Plant and Shandong Haiyang Nuclear Power Plant under construction in China are the first projects in the world to adopt AP1000 nuclear power technology. For the first time, engineering construction adopts modular construction. Regardless of equipment manufacturing, module construction, or engineering construction, welding quality is safe for nuclear power plants. It plays a vital role, and the welding documentation directly affects the quality of the weld. Therefore, as the main organization of engineering management, JPMO (Joint Project Management Organization) pays great attention to the quality of welding documents. In practice, it has proven effective welding document review measures and effectively prevented and corrected defects due to welding documents. Caused by welding quality problems and non-conformities.

In addition, AP1000 nuclear power plant design, equipment manufacturing and engineering construction mostly use American standards, many types of materials, common low-alloy high-strength steel, stainless steel, forged steel and non-ferrous metals; welding methods used are SMAW, SAW, GMAW, FCAW, GTAW, etc.; not only the standards and requirements for welding of modules, equipment and process pipes have their own characteristics, but also the welding documents are all written in English according to the contract requirements.

2. Common welding file types for AP1000 nuclear power engineering

The construction of nuclear power projects requires "four things", that is, "everything has rules to follow, everyone is responsible, everything is well documented, and everything is supervised." Welding as a special process, whether it is China's nuclear safety regulations and guidelines, or the US quality and technical standards, and even Westinghouse technical specifications, put strict requirements on welding documents. Welding documents are the rules that must be followed in welding-related activities, and are an important manifestation of all things to follow. The AP1000 nuclear power engineering welding documents usually include two types of management documents and technical documents. The management documents are the guarantee for the effective implementation of technical documents. The technical documents are the basis for meeting the welding quality requirements.

Management documents typically include: general welding management procedures, welding procedure qualification management procedures, welding material management procedures, welding rework procedures, welder and welding operator management procedures, heat treatment management procedures, weld numbering systems, and welder skill assessment reports and welders Qualification forms, etc.; technical documents usually include: welding consumables procurement procedures, WPS and PQR, welding and heat treatment schemes, thermal cutting technical regulations and welding deformation control measures.

3. Prerequisites for document review

The correct implementation of the following tasks is a prerequisite for the welding documentation review: 1 contract signing or contractor to obtain an order. 2 The quality assurance program or quality manual is approved. 3 Design drawings are approved. 4 For technical documents, the relevant management documents are approved. 5 Auditors are familiar with relevant regulations, standards, etc.

4. Highlights of the document review

Prior to the start of the welding activity, the relevant documents must be reviewed and approved by the JPMO welding engineer. Correct, applicable and effective welding documents shall meet at least the following requirements:

(1) Integrity First, the identification of the file should be complete, that is, the identity (name, code, version, etc.) and status identification (controlled, PRE, CFC, executable, etc.) of the file are complete; secondly, the content of the file should be complete. The necessary requirements and elements are complete, the work content, control measures, and the responsibilities of the sponsoring department are clearly defined. The interface between the cooperating department and the affected units of the participating departments is clear; finally, the necessary records should be provided, such as Weld return record records, WPS tables, etc., provide objective evidence for welding activities and welding quality to meet the requirements, to ensure that the evidence is available.

(2) The content specified in the conformity document shall meet the requirements of the quality assurance outline or the quality manual, meet the requirements of standards, specifications and technical specifications; the documents have good compatibility, not only must be coordinated, no contradictions, And to be clear to meet the welding quality control requirements.

(3) Nouns, terms, abbreviations, etc. in the same document should always be uniform, the same noun should have no double meaning, the Chinese and English expressions of bilingual documents should be unified, and the dominant language types should be pointed out, such as: a welding procedure document In the "Environmental Temperature Requirements" column, fill in "RT", and in the subsequent "Inspection" column, also fill in "RT", the former means "Room Temperature", the latter represents a non-destructive testing method, ie "Radiographic Testing" is therefore easy to cause misunderstandings by file users.

(4) The validity document shall be prepared, reviewed, approved, and signed by the qualified or authorized personnel. The document shall have a declaration that meets the requirements of the relevant standards and regulations. For example, the PQR in accordance with ASME IX shall have a similar Proof that the document is recorded correctly and completely, and the weld is prepared, welded and inspected in accordance with ASME IX.

(5) The correctness of the welding document should clarify the scope of its application, the standard specifications to be followed, and the technical parameters, important variables, and important variables to be added should be scientific and reasonable, meet the requirements, be in line with the actual conditions, and should also indicate the applicable if necessary. Minor changes and special requirements.

(6) Readability documents and materials should be written in the prescribed format, with clear writing and icons, simple and clear language expression, strong logic and easy to understand.

5. Basis for review

As the AP1000 nuclear power plant constructed in mainland China and designed according to American standards, its equipment manufacturing and construction activities must comply with China's laws and regulations, and also comply with the relevant technical standards of the United States. Therefore, the basis for the review of welding documents includes at least: China's nuclear safety regulations and related guidelines, such as: HAF603, HAF003 and HAF602. 2NI contract, PR. 3 technical standards, such as: ASME II, ASMEIII, ASME IX, AWS D1.1, AWS D1.6, etc. 4 Westinghouse technical specifications, CFC status drawings and design changes. 5 Supplementary warranty requirements CPP-GV1-GAH-001, CPP-GV1-GAH-002. 6 approved quality assurance program.

6. AP1000 nuclear welding document review process

The AP1000 nuclear power welding document review was carried out by JPMO on the “document” management platform developed by Westinghouse. The document review process is shown in the figure. After receiving the welding package from the equipment manufacturer or the engineering builder, the JPMO welding professional engineer determines the priority of the document according to the progress of the project. The difference is whether the document is submitted for the first time or after the revision, and then the management file is determined according to the nature of the document. It is also a technical document to understand the US standards and their editions to be followed (usually based on the ASEM 1998 version of the document), as well as the technical specifications and design drawings provided by Westinghouse; collect and familiarize with national nuclear safety regulations and related guidelines. Then, the requirements of relevant technology and management documents are reviewed according to the review points proposed in this paper, comments are made, and the document provider is communicated in order to reach an agreement. Finally, the AE engineer approves the review opinions and seals them.


Document review process

7. Conclusion

According to the principles and methods described in this paper, through the review of the AP1000 nuclear power engineering welding documents, not only the equipment and engineering welding quality is effectively improved, but also the equipment manufacturing and engineering construction progress is guaranteed, and the inspection of other engineering welding documents is very Good reference value.

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