6. Efficiency Improvement of Perio die Inspection Work 4-25

3. Maintenance Against Plant Aging 4-26

1. Technical Study on Aging 4-26

2. Maintenance Technology against Aging 4-29

3. Upgrading by Facility Replacement 4-35

Chapter 5 Operation and Maintenance of PWR Plants

1. Plant Operation 5-1

1. Reactor Control Systems 5-1

2. Plant Star tup 5-2

3. Plant Normal Operation 5-5

4. Operator Activities during Plant Normal Operation 5-9

5. Plant Shutdown 5-10

6. Chemical Control 5-11

2. Plant Maintenance 5-13

1. Maintenance Management Policy 5-13

2. Periodical Inspections and Periodical Utility Inspections 5-14

3. Maintenance during plant normal operation 5-25

4. Rationalization of Plant Features Related to Periodical Inspections 5-25

3. Maintenance to Cope with Plant Aging 5-27

1. Technical Evaluation of Aging Effects 5-27

2. Maintenance Techniques to Cope with Plant Aging 5-27

3. Upgrading of Plants by the Renewal of Systems 5-30

Chapter 6 Radiation Control

1. Purposes of Radiation Protection 6-1

2. Regulation for Radiation Protection 6-1

1. Legislative System for Radiation Protection 6-1

2. Specific Applications of Legislation 6-3

3. Radiation Sources at NPPs 6-3

1. Actual Conditions concerning Radiation Sources 6-3

2. Behavior of Radioactive Materials at NPPs and Protective Measures 6-9

4. Design Base for Radiation Protection Facilities 6-9

1. Design Base Dose 6-9

2. Shielding Design Base 6-9

5. Area Control 6-10

1. Standards of Area Control in Accordance with Legislation 6-10

2. Classification of Controlled Areas 6-11

3. Confirmation of Radiation Environment 6-12

4. Access to and Exit from Controlled Areas 6-12

6. Work Management 6-13

1. Study of Work Methods 6-13

2. Approval of Radiation Work 6-14

3. Confirmation of Work Environment 6-15

4. Completion of Work 6-15

5. Fu ndamentals of Radiation Protection for Work Management 6-17

7. Controls of the Individual 6-17

1. Qualification of Radiation Workers 6-17

2. Evaluation of Individual Dose 6-18

3. Targetof Individual Dose Control 6-19

4. Records of Individual Dose 6-19

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5. Track Record of Individual D ose 6-19

8. Radioactive Waste Management 6-24

1. Radioactive Solid Wastes 6-24

2. Radioactive liquid Wastes 6-25

3. Radioactive Gaseous Wastes 6-31

9. Environmental Radiation Monitoring 6-33

Chapter 7 Safety Evaluation of BWR Plants

1. Basic Policy for Safety Evaluation 7-1

1. Objectives of Safety Evaluation 7-1

2. Method of Safety Evaluation 7-1

2. Anticipated Operational Occurrences 7-5

1. Assumption of Event 7-5

2. Abnormal Withdrawal of Control Rods during Reactor Startup 7-6

3. Loss of Feed Water Heater 7-8

4. Loss of Load 7-8

5. Features of ABWR Transient Analysis 7-9

3. Accidents 7-10

1. Assumption of Events 7-10

2. Loss of Reactor Coolant (in case of a Large Break) 7-10

3. Main Steam line Break 7-12

4. Dose Assessment for Accidents 7-12

5. Characteristics of ABWR Accident Analysis 7-13

4. Major Accidents and Hypothetical Accidents 7-14

1. Assumption of Events 7-14

2. Loss of Reactor Coolant 7-14

3. Main Steam Line Break 7-14

4. Dose Evaluation 7-16

5. Probabilistic Safety Assessment (PSA) for BWRs 7-18

1. PSA during Operation 7-18

2. PSA during Shutdown 7-20

6. Severe Accident 7-20

Chapter 8 Safety Evaluation of PWR Plants

1. Basic Principles for Safety Evaluation 8-1

1. Purposes of Safety Evaluation 8-1

2. Methodology for Safety Evaluation 8-1

2. Abnormal Transients during Operation 8-4

1. Postulation of Events 84

2. Partial Loss of Reactor Coolant Flow 8-5

3. Uncontrolled Control Rod Withdrawal at Reactor Startup 8-6

4. Loss of Normal Feedwater Flow 8-6

3. Accidents 8-9

1. Postulation of Events 8-9

2. Loss of Reactor Coolant 8-9

3. Steam Generator Tube Rupture 8-11

4. Dose Evaluation in Accidents 8-12

4. Major Accidents and Hypothetical Accidents 8-13

1. Postulation of Events 8-13

2. Loss of Reactor Coolant 8-13

3. Steam Generator Tube Rupture 8-16

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