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Chapter 10 Quality Assurance (QA)

concerning the achievement of nuclear safety.

  1. Conformity to product and work requirements.

  2. Characteristics and trends of processes and nuclear facilities including opportunities for preventive action.

  3. The ability of suppliers judged from the situation of nonconformities in the purchased products and of their audited results, etc.

  1. Nonconforming Control & Corrective Action

Actions on the detected nonconformities and corrective actions to prevent their recurrence are not carried out individually but are usually carried out as a part of a series of activities in the quality management system. Corrective actions are also one of the improvement activities. Thus it is important that nonconformities are not hidden as an inconvenient matter but are exposed and then are tied in well with the correction, to make the organization activities better.

(1) Nonconforming control

i ) General points

When nonconforming products or services are detected at each stage from the design to operation and maintenance, they are identified and controlled to prevent their unintended use or direct acceptance. The identification and control methods for a review and actions as to

their subsequent handling must be defined in a documented procedure.

ii ) States and events of nonconforming products or services

Nonconforming products or services present the state in which products or services provided do not meet their specified requirements (for example, specifications, instruction manuals, etc.). The following are examples of states and events dealt with in nonconformity control.

  1. Quality characteristics beyond the specified value. For instance, deviation from required specifications of material size and properties, installation error, performance defect of equipment and system, etc.

  2. Deviation from specified process parameters or work instructions, etc.

  3. Human errors in work, inspection, or conducting a test by its test instruction manual

  4. Inappropriate documents which contain inaccuracies or incomplete information

  1. Nonconformity identification

Nonconforming products or services are identified to prevent their unintended use or direct acceptance.

They include the following.

  1. Marking with paint, etc. : Welding defect, casting defect, etc.

  2. Tagging : Part defect, attachment defect, measuring device defect, and valve defect, etc.

Act

Plan

Analysis of data and improvement (See. 10,10)

  1. Analysis of data.: ;

  2. Nonconforming - I action1 corrective action:

  3. Preventive action :

Check

Monitoring & measurement and internal audit (Sec.10.9)

Product realization(Sec.L0.5) Production and service provision (implementation of work) (Sec. 10.8)

Do

Design and development (Sec. 10.6)

Purchasing (Sec. 10.7) ; Production and service provision

(implementation of work) (Sec. 10.8)

Figure 10.10.1 pdca cycle for product realization in the quality management system

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NSRA, Japan

  1. Isolating : Necessary components of the welding repair, leak point, etc.

  2. Recording in documents : For services

  3. Other appropriate methods : For services

The organization carrying out the identification indication (including the elimination of the nonconforming state after the correction) must also be clarified.

  1. Nonconformity evaluation, action and re­verification after corrections

For the nonconforming products or services, the nature and the effects of their nonconformities are evaluated and the actions as to their subsequent handling are decided according to the provided procedure. The evaluation and action activities might be decided in a special committee or conference meeting according to the content of non-conformities. Techniques for the management of non-conformities include the following.

  1. Defining the responsible person for evaluation and the authorized person for action decisions

  2. Evaluating and reviewing the effects of the nonconforming products or services

  3. Procedures for actions including establishing report forms, report making, and establishing report route, etc.

  4. Nonconforming actions

  5. Conforming product making by eliminating nonconformities including reuse or acceptance by repair, refabrication or correction

  6. Authorizing the following actions under concession by a relevant authority (or, where applicable, by the customer) : Use without modification, release (delivery to the next process), or acceptance

  7. Taking action to preclude its original intended use or application : discarding the object or using it for a different application

  8. Re -verification after correction including reevaluation, or re-inspection and testing, reviewing the revised document, etc.

  1. Maintaining records on the nature of nonconformities

As objective evidence for nonconforming actions, the following are maintained: records of the nature of nonconformities and any subsequent actions taken, records of concessions obtained.

Furthermore, a ’’Nonconforming report” is a general report for the records of the nature of nonconformities; it includes a report of the nonconformities, decisions on actions to be taken, records of actions taken, records of re-verification, etc.

  1. Nonconformity detected after delivery

When a nonconforming product was detected after delivery or after the beginning of its use, appropriate actions are taken as to the effects or potential effects of the nonconformity.

(2) Corrective action

i ) General

In order to prevent the recurrence of nonconformities, corrective actions must be taken to determine and eliminate the causes of nonconformities. Therefore a control method must be established to develop, determine and implement corrective actions.

From the viewpoint of the prevention of the occurrence of nonconformities beforehand, attention must be turned to the tendencies for results of quality performances, or to changes in tendencies for the occurrence of nonconformities in mass produced products. It is important to clarify the causes of these tendencies and changes, and then to determine and implement corrective actions needed.

In addition, corrective actions must be appropriate to the effects of the conformities encountered, and they are extremely important to perform the continuous improvement of the effectiveness of the quality management system,

  1. Reviewing the nature and identifying the causes of nonconformities

Preceding the determination of corrective actions, it is important to review the nature of nonconformities and to identify the causes of their occurrence.

It is important to investigate and pin down the exact reason for nonconformities by identifying not only the occasion factor but also the underlying, the latent, or even the root causes. This process is called "Root cause analysis". The mechanism of the event occurrence and the root of the factors hiding behind it are clarified by investigating the factors of the event occurrence

NSRA, Japan

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