establishment of systematic design control /configuration ... · configuration change control...

©Tokyo Electric Power Company Holdings, Inc. All Rights Reserved.

8 / Nov / 2016

Third International Conference on Nuclear Knowledge Management：Challenges and Approaches

Takafumi Ihara

Tokyo Electric Power Company Holdings, Inc.

Establishment of Systematic

Design Control /Configuration Management

Processes to Enhance Engineering Capability

©Tokyo Electric Power Company Holdings, Inc. All Rights Reserved. 1

Configuration Management is a process to ensure

the consistency among three factors below.

Configuration Management

Design

Requirements

What is

required to be

there

Facility

Configuration

Information (FCI)

What is

documented

Physical

Configuration

What is actually

there

Fig1： Three Ball Model


Points to be improved in Our Design Engineering

2

We have managed design change process in accordance with

procedure, but sometimes it is difficult to understand the core

information of design as below clearly. Therefore it may occur

that we can’t take responsibility of design change. Design Bases

Design Process Information, e.g. Process Calculation, Stress Calculation

Important drawings on physical configuration such as cable routes

Engineering Decisions are highly dependent on plant

manufacturers and tacit knowledge in the limited number of

experienced TEPCO employees.

It is difficult to precisely pick up the documents which are

required for and affected by the design change because the

relation between equipments/systems and those documents

are not well defined.


Cable Lay-down Case under the MCR Floor

3

At Fukushima-Daini NPP and Kashiwazaki-Kariwa NPP, safety-related

cables were found to have been laid together with non-safety cables or

separation between different divisions were removed/ unfunctioned by

Putting a new cable over the separation plate

Felling the separation plate

Breaching the separation plate

That violated the regulation which called for their independency and

redundancy.

Appropriate Cable Route

Observed Cable Route

Horizontal Separation Plate

Vertical Separation Plate

MCR Floor

Division Labels

Fig2： Example of cable lay-down under the floor of the MCR (Kashiwazaki-Kariwa Unit 6)


Separation

Plate

Safety

Division

Non-safety

Division Separation

Plate

Safety

Division

Fig3： Examples of appropriate and inappropriate cable lay-downs

Appropriate Cable Lay-down Inappropriate Cable Lay-down

Cable Lay-down Case under the MCR Floor (Cont’d)

Non-safety

Division


What was the projected consequence?

If a problem such as fire occurs to one cable, safety

systems of the different divisions simultaneously may

lose their function. (Common Cause Failure)

Why it happened? (Deficiencies in the design management

and configuration management processes)

TEPCO didn’t sufficiently realize the importance of three

things as below.

1. Design Requirement：Not clearly informed to the contractors

2. Insufficient review of design change documents

3. No inspection on as-built Status

Cable Lay-down Case under the MCR Floor (Cont’d)


Improvement Program

6

Define the design requirements,

and compile them in the documents

Establish a process to maintain

consistency among three factors

Establish and maintain the

Master Equipment List

Define what is FCI and Determine

how to manage FCI

P.7 Design Requirement Control

P.9 Configuration Change Control

P.8 FCI Control

P.8 FCI Control / Document Management


Design Criteria Document （DCD） Design Bases

Design Specification 1

Design Specification 2

Design Requirement Control

7

Define & Integrate all the design requirement in the Design Criteria

Document (DCD).

Manage the relations that

- which requirement in DCD is supported by which Design Bases

(regulation, code, standard or engineering documents) and

- which requirement is applied to which Design Specification

not to get scattered and lost the important design information.

Fig4： Illustration of Design Requirement Control

Design Bases

(Regulation, Standard, etc.)

Design Criteria Document

（DCD） Design Specification


FCI Control / Document Management

8

Establish the Master Equipment List (MEL) and put it as core of

configuration management to manage the relation between all the

documents and systems/components in MEL. (MEL-Document relation)

Establish the relation among documents for the convenience of impact

analysis, in which engineers can easily judge which documents should

be examined for revision if one document has been revised.

Fig5： Illustration of design / component document relation tree and impact analysis


Configuration Change Control

9

Prepare the work process to maintain consistency among three factors.

(Prepare process for the case of document change only)

Manage a series of change work by a system to grasp the past change

history and the changing work status easily.

Set all the necessary tasks at planning phase, and manage them so

that there would be no omission of change work.

Fig6： Illustration of configuration change control


Configuration Management Support System

10

Fig7： Configuration Management Support System


Summary

11

We consider key attributes of the systematic design management/

configuration management process and its system are the following

four items.

Design Requirement Control

FCI Control / Document Management

Configuration Change Control

Configuration Management Support System

By introducing the systematic configuration management process,

we would be able to clearly understand the design requirements and

their bases, and can take responsibility for the plant design.

With the retirement of experienced employees, the know-how and

knowledge that they had may be lost so far. Therefore it is quite

important to establish systematic design management/ configuration

management processes to get reduce dependency on their

personal experience and knowledge.


Configuration management would also be effective to train the new

employees because they can access the comprehensive design

information easily.

Challenges to establish the systematic design management/

configuration management processes are as follows:

Cooperation from the original manufacturers is essential to

obtain missing information and documents, concerning design

requirements and their bases.

Inputting huge amount of information is necessary to

introduce relevant data in the system, such as data on

relations among documents, MEL, etc.

(Phased approach will be implemented for this establishment)

Summary (Cont.)

establishment of systematic design control /configuration ... · configuration change control...

Documents