KAERI

안전설계지침에

I그

τr

CANDU9 격 납건물확장부의

제출합니다.

줄저|

구l 하한국원자력연구소장

보고서를

기술보고서로한

본

대

CANDU9 격납건물 확장부의 안전설계지침

(Safety Design Guide for Containment Extension

for CANDU 9)

기술관리분야

3월

울진5，6호기

1996년

제출부서명:

제목

./-‘.-A I­

01A.C.D. Wright (AECL, Toronto)

。킥C그

드「C그.-남

01자:A-ic=>작

석수동

(개 량중수로개발분야책임 자)

7 1- ~ £.1 。냐I그 .- τ-\ I':코

(연구위원)훈.s=.〈그

.7 1C그

책임감수위원 :

요 약

인.허가는 규제기관이 원자력 발전소의 부지사용인가， 건설학가， 시운전 및

운영허가서 등을 발급하는데 필요한 안전상의 보증을 제공하기 위하여 수행되는

행위여다.

전통적으로， 캐나다의 규제가관인 AECB는 일반적인 요건딴을 제서하는

방안을 채돼하여 왔으며， 상세한 규제요건은 인허가 전 과정을 통하여 적용된다.

기존의 발전소에서 발견되는 설계/운전상의 결함차료를 통하여 AECB의 지식이

점점 축적되어， 새로 건설되는 발전소에 적용하고자하는 요건이 점차 증가되는

추세를 보이고 있으며 이것여 CANDU 원자력발전소의 언허가 관행이다.

규제기관이 건설허가를 발급하는 데 있야， 1차적으로 고려하는 사항은 설

계내용이 안전요건을 만족시키고 있는가에 대한 확산을 갖는 것이다. 이를 위하

여 특정 가상사고에 대한 안전해석이 수행되고 그 결과를 평가할 수 있도록 충분

히 개선된 설계가 이루어 져야 한다.

CANDU획 인허가 과정에서 일반적으로 요구되는 몇 가지 정보가 었으며，

그중 안전설계지침(Safety Design Guide)은 발전소의 안전관련계통에서 만족시켜

야 할 필수적인 설계요건/표준을 정의하는 설계지침이다. 이들 셜계지침은 규제

요건애 부합하도록 셜계되었는지 확인하고 일련의 설계결과물(서류)의 포괄성을

보증하기 위하여 규제기관에 의하여 검토된다.

본 “격납건물 확장부의 안전설계지침”에는 격납검물의 격리원리와 격납건

물 확장부의 요건을 서술하고 있다. 금속확장부와 ASME Section ill 의 범주에

속하는 기거들은 CAN/CSA-N정5.0 과 CAN/CSA- N285.3에 따라 안전등급을 분

류하였다. 또한 누설감시능력 내진설계요건 그리고 격납건물확장부의 검사요건등

이 본 안전설계지침에 정의되었다. 아울러 배관계통 관련요건을 포함한 격납건물

격리요건을 규정， 요약하여 부록에 표가하였다. 추후 규제기관의 규제요건， 코드

및 표준의 변경을 지속적으로 추적하여야하며 본 안전설계지침도 요건의 변경에

따라 개정되어야 한다.

ABSTRACT

Licensing is the activity which is undertaken to provide the necessary assurances of safety to the regulatory agency so that they may issue appropriate certifications for site approval, construction, commissioning and operation of the nuclear facility.

Through tradition, the AECB, regulatory body of Canada, has chosen to issue only general regulations. Specific regulatory requirements are applied through the licensing process. These requirements tends to increase with each new station as the AECB gains more knowledge and data about design/operational deficiencies in existing plants, and this is a traditional licensing practice of the CANDU nuclear power plants.

The regulatory body's primary concern in granting approval to commence construction is to assure itself that the design meets the safety requirements. In order to this it is necessary that the design be in a sufficiently advanced state to enable safety analyses of a specified set of hypothetical events to be performed and their results assessed.

There are several information generally required as part of the licensing process, and among them, Safety Design Guides are guides(prepared by utilities) which defines mandatory design requirements/standards to be met by safety related system of the plant. These design guides are reviewed by the regulatory body to verify compliance with the regulatory requirements and to ensure that the series of documents is sufficiently comprehensive.

This Safety Design Guide for Containment Extension describes the containment isolation philosophy and containment extension requirements. The metal extensions and components falling within the scope of ASME Section HI are classified in accordance with the CAN/CSA-N285.0 and CAN/CSA-N285.3. The special consideration for the leak monitoring capability, seismic qualification and inspection requirements for containment extensions, etc., are defined in this design guide. In addition, the containment isolation systems are defined and summarized schematically in appendix A. The change status of the regulatory requirements, code and standards should be traced and this Safety Design Guide shall be updated accordingly.

TABLE OF CONTENTS

SECTION PAGE

1. SCOPE 1

2. COMPLIANCE 2

3. CONTAINMENT ISOLATION PHILOSOPHY 3

3.1 General 3

3.2 Containment Extensions 3 3.3 Containment Isolation 3 3.4 Seismic Qualification 4

4. CONTAINMENT EXTENSION REQUIREMENTS 5

4.1 GENERAL 5 4.2 Containment Boundary 5 4.3 Containment Isolation 6

5. DOCUMENTATION 7

Appendix A Acceptable Containment Isolation Barriers 8 Appendix B List of Safety Design Guides 15

1. SCOPE

The purpose of this document is to identify the requirements for metal extensions of the containment boundary, and the requirements for isolation of containment during accident conditions.

It should be noted that not all requirements are specifically mentioned in this Safety Design Guide, and that these are addressed in the referenced documents (particularly AECB Regulatory Policy Statement R-7 (Appendix and CAN/CSA-N285.3).

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2. COMPLIANCE

Compliance with Safety Design Guides is mandatory. A listing of Safety Design Guides is included in Appendix B. Deviations from the requirements identified in the guide may be allowed, after they are reviewed approved by completion of a Safety Design Guide Supplement, form PP-729.

The above recognizes that a safety function can be performed in several alternative ways, and that the designer should be free to choose the most efficient and economical design that meets the safety requirements. It also ensures that any such deviations are documented and checked for compatibility with the overall safety philosophy.

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3. CONTAINMENT ISOLATION PHILOSOPHY

This section of the Safety Design Guide describes the safety concept and safety design philosophy used to develop the safety requirements. It is to be considered as information for the interpretation and application of the safety requirements listed in section 4.

3.1 GENERAL

The containment envelope, also referred to as the containment boundary, includes the concrete containment structure and the metallic extensions attached to the concrete structure needed to form a continuous barrier between the containment volume and the outside environment, through which many different fluid and electrical systems must pass. These metallic extensions may also include various types of nonmetallic seals to satisfy the leakage requirements. This Safety Design Guide identifies the requirements applied to these metallic containment extensions.

3.2 CONTAINMENT EXTENSIONS

Containment extensions are designed to satisfy the requirements of the AECB Regulatory Policy Statement R-7 and the Canadian National Standards CAN/CSA N285.0 and N285.3.

According to N285.0 and N285.3, metal extensions are primarily classified as Class 2 (piping components) or Class 4, and components falling within the scope of ASME Section III are designed to satisfy Class 2 or Class MC. Class 6 is also permitted for closed systems inside the reactor building which penetrate the containment boundary, with additional restrictions on the design pressure, operating pressure and leak monitoring capability.

In the design of extensions, the leak monitoring capability is considered to be any method by which the operator can detect a leak in the pressure boundary (containment boundary) of the extension within a reasonably short time period (i.e. one day), so that repairs or additional isolation can be established to re-establish the integrity of the containment boundary.

The extensions are inspected in accordance with the requirements of CAN/CSA N285.5. The containment envelope, including the metallic extensions, is seismically qualified to the Design Basis Earthquake (see Safety Design Guide for Seismic Qualification).

3.3 CONTAINMENT ISOLATION

The requirements for containment isolation are included in the Appendix of AECB Regulatory Policy Statement R-7 and are summarized below.

Fluid systems penetrating the containment envelope must form a reliable barrier against releases inside the containment envelope, or must be equipped with suitable isolation devices. These systems consist of two types :

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a. closed systems, which penetrate containment and for which the fluid in the system does not communicate with the containment atmosphere or heat transport coolant (e.g.service water system). A "closed system" is defined by AECB R-7, clause 1 as "a piping system which penetrates and forms a closed loop or an enclosed volume either inside or outside the containment structure. For closed systems inside containment, the fluid in the system does not directly communicate with either the primary coolant or containment atmosphere". Systems which do not satisfy this definition are considered to be open systems. Closed systems built to Class 2 requirements and continuously monitored for leaks require no further isolation. Where leak monitoring is not possible a single valve must be provided immediately outside the containment structure which can be manually closed in the event of leakage of the boundary.

b. open systems, which penetrate containment and for which the fluid is in direct contact with the containment atmosphere or the heat transport system during normal or accident conditions. Open systems require two isolation valves in series, except for small lines 25 mm diameter and under connected to the primary heat transport system or 50 mm diameter and under for lines connected to the containment atmosphere, which need only one closed valve when connected to a normally closed system outside containment. For lines connected to the primary heat transport system one valve should be located inside the containment structure and one outside, and at least one must be either automatically closed or a powered valve operable from the control room. For lines connected to the containment atmosphere, two automatically closing valves are required for normally open lines, both of which may be located outside the containment structure, or two closed valves for normally closed lines.

Closed isolation valves must either be locked closed or continuously monitored. However, normally closed valves which form part of the boundary of a closed system are not required to meet this requirement, as long as their open condition can be detected and is controlled by strict administrative procedures during normal plant operation. Relief valves may be part of a closed system as long as they will automatically reclose after an overpressure condition.

3.4 SEISMIC QUALIFICATION

The containment boundary must be maintained during and after an earthquake, both for the Design Basis Earthquake (DBE) and for the Site Design Earthquake occurring 24 hours after a loss of coolant accident (see Safety Design Guide for Seismic Qualification).

The seismically qualified boundary must include two isolation valves for fluid lines that are normally open at the time of the seismic event, and a single closed isolation valve for lines that are normally closed at the time of the event

4. CONTAINMENT EXTENSION REQUIREMENTS

4.1 GENERAL

a. Containment extensions, consisting of systems, or sections of systems, which form part of the containment boundary, shall satisfy the requirements of AECB Regulatory Policy Statement R-7 "Requirements for Containment Systems for CANDU Nuclear Power Plants", CAN/CSA-N285.0 "General Requirements for Pressure Retaining Systems and Components", and CAN/CSA-N285.3 "Requirements for Containment System Components in CANDU Nuclear Power Plants".

b. Containment extensions shall be seismically qualified in accordance with the "Safety Design Guide for Seismic Qualification", according to the following criteria:

1. For fluid systems in which the isolation valves are open, and which are also open to the containment atmosphere or connected to primary heat transport system, two isolation barriers (i.e. two open valves) shall be qualified to close during or after the DBE.

2. For fluid systems in which the isolation devices are normally closed or which form closed systems inside or outside the containment structure, only one isolation barrier (i.e.one closed valve) is required to be qualified to the DBE.

c. Acceptable seismic qualification of containment extensions and isolation barriers is indicated in Appendix A for various configurations. Other configurations for the seismically qualified boundary may also be used, including the use of manually operated valves, where the dose limits can be shown to be satisfied and the valves or valve controls are accessible after the event.

4.2 CONTAINMENT BOUNDARY

a. Containment extensions consisting of portions of fluid systems (including the portions of piping from the penetration seal plate to the point of isolation) shall be classified as Class 2 of CAN3-N285.0, except for :

1. Systems or components that are Class 1 2. Closed systems inside the containment structure (reactor building) may be Class 6 if the

following conditions are all met: i. their design pressure is greater than 0.5 MPa(g), ii. they are operated continuously at or above the design pressure of containment, iii. they are monitored for leaks.

3. Closed systems may be Class 3 if the design provides an adequate barrier (e.g. smallness of size) and it is submitted to and accepted by the regulatory authority.

b. The leak monitoring capability required for closed systems shall be capable of detecting leaks from the closed system, and may consist of makeup tank level measurements, detection of system inventory on the floor or in sumps, increased vapor recovery, etc.

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c. Closed systems shall be defined in accordance with AECB Regulatory Policy Statement R-7 (i.e. "closed system means a piping system which penetrates and forms a closed loop or enclosed volume either inside or outside the containment structure. For closed systems inside containment, the fluid in the system does not directly communicate with either the primary coolant or containment atmosphere"). All other systems shall be considered to be open systems (note that a system having an open vent inside the containment structure is an open system).

d. Relief valves which reclose after an overpressure condition and normally closed valves which can be confirmed closed by the leak monitoring capability or by administrative procedures can form part of the pressure boundary of a closed system with no further monitoring or locking devices (however, note that closed system isolation valves must be locked closed or monitored per 4.3 (3))

4.3 CONTAINMENT ISOLATION

a. The isolation barriers for metal extensions of the containment envelope shall satisfy the requirements outlined in AECB Regulatory Policy Statement R-7 "Requirements for Containment Systems for CANDU Nuclear Power Plants". The requirements for piping systems are defined in the Appendix of that document, and are summarized and shown schematically in Appendix A, but R-7 should be consulted directly for situations that differ from those described.

b. Where a closed manual isolation valve is used to satisfy containment isolation requirements, it must be locked closed or continuously monitored. Where an open isolation valve is used, the valve shall be designed to be tested periodically and the valve leakage shall be shown to be within acceptable limits. Leakage criteria for isolation valves shall be established and documented.

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5. DOCUMENTATION

a. Containment extensions and their code classification will be indicated on system flowsheets and in Design Descriptions in the detail design stage.

b. A listing of containment extensions will be provided in the Design Description for the Containment System in the detail design stage.

c. Details of the inspection of containment extensions, as required, will be specified in "Periodic Inspection Program for Containment Components" in the detail design stage.

d. Where the containment extension is part of a pressure retaining system, the code classification shall be shown in "System Classification List", which will be prepared in the detail design stage.

APPENDIX A

ACCEPTABLE CONTAINMENT ISOLATION BARRIERS

The following summarizes the requirements of AECB Regulatory Policy Statement R-7 (Appendix) and provides typical figures for each case.

a. Systems Open to the Containment Atmosphere

Systems connected to the containment atmosphere shall be provided with isolation barriers (normally located outside the containment structure), as follows-

1. Two automatically closing valves (see Figure 1(a)) Two automatically closing Class 2 isolation valves, one of which may be a check valve, for lines that may be open to the containment atmosphere (a valve is "automatically closing" if it is closed by the containment isolation system signal, or is closed directly by a condition caused by the accident or a system characteristic, with no operator action). Both valves shall be seismically qualified to close during the Design Basis Earthquake (DBE).

2. Two closed valves (see Figure Kb)) Two closed Class 2 isolation valves, for lines normally closed to the containment atmosphere. Only one valve needs to be seismically qualified for the DBE.

3. One closed valve (see Figure 1(c)) One closed Class 2 isolation valve, for lines of diameter 50 mm nominal (NPS 2) or less, normally closed to the containment atmosphere and connected to an easily defined closed system outside containment. The valve and piping up to the seal plate at the containment structure shall be seismically qualified for the DBE.

4. No isolation valve (see Figure 1 (d)) Closed piping systems that satisfy the following need no further isolation: i. The containment boundary components are Class 2 ii. The system is continuously monitored for leaks

The closed system shall be seismically qualified for the DBE. 5. Instrument Tubing (see Figure 1(e))

This is a special case of 1 (d) above, where it may not be possible to provide leak monitoring and where a closed valve cannot be used because a safety function must be maintained. The instrument and tubing forms a closed system, Class 2 or higher code class, and an open valve or crimping is required for isolation.

The instrument, valve, and piping up to the seal plate at the containment structure shall be qualified for the DBE.

b. Systems Closed to the Containment Atmosphere

Systems which penetrate the containment boundary and are closed systems within the containment structure shall be provided with isolation as follows :

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1. No isolation valve (see Figure 2(a)) Closed Class 2 systems inside the containment structure, seismically qualified and monitored continuously for leaks need no isolation valves. If leakage monitoring cannot be provided, a single manual isolation valve shall be provided outside the containment structure. The valve may be used for other process purposes, but must be accessible after an accident The closed system shall be seismically qualified for the DBE.

2. One isolation valve (see Figure 2(b)) Closed Class 6 piping systems inside the containment structure which satisfy the design and operating pressure requirements for Class 6 systems, and which are monitored for leaks, shall be provided with a single manual isolation valve. The closed system shall be seismically qualified for the DBE. As an alternative, the isolation valve and piping to the seal plate at the containment structure may be qualified.

c. Systems Connected to the Heat Transport System

Systems which penetrate the containment boundary and are connected to the primary heat transport system shall be provided with isolation as follows:

1. Open Isolation Valves Systems having normally open lines shall be provided with two isolation valves, Class 1, one of which can be manually closed from the control room or is automatically closed. A check valve located inside the containment structure is an acceptable automatically closing valve. Both valves shall be seismically qualified.

2. Closed Isolation Valves Systems having normally closed lines shall be provided with two normally closed isolation valves. A check valve located inside the containment structure may be used as one of the isolation valves. The piping inside the containment structure, up to the seal plate on the containment boundary shall be seismically qualified. Alternatively, the valve and piping up to the seal plate outside the containment structure may be seismically qualified, if it is shown that the operator can close the valve before a release of radioactive material can occur.

3. Small Lines (25 mm diameter or less) A single closed Class 1 isolation valve located inside the reactor building may be used for small lines that are normally closed. The line from the valve to the seal plate at the containment boundary shall be Class 2, and connected to a closed system outside the containment structure. The valve and piping up to the seal plate at the containment structure shall be seismically qualified for the DBE.

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4. Instrument Lines This is a special case of 3(c) above, where it may not be possible to provide a closed valve in order to maintain a safety function. The tubing up to the instrument shall be Class 1, and an isolation valve outside the containment structure shall be provided (the instrument isolating valve is an acceptable isolating valve, provided the instrument as close as practicable to the containment structure). The instrument and tubing shall be seismicaily qualified.

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FIGURES

Systems Open to the Containment Atmosphere

1 (a) : Two Automatically Closing Valves

•fe /

1 (b) : Two Closed Valves

Class 2

- DBE

- f > K ^

Containment boundary (typical)

Inside Containment

(One or both valves may also be inside containment)

DBE

£ Class 2

Inside Containment

(One or both valves may also be inside containment)

1 (c) : One Closed Valve

Diameter 50 mm or less

Closed System • « \ | »- Class 2 ^

DBE ^ j -

Inside Containment

Closed system under normal

— - Class 6

1 (d ) : No Isolation Valve

Conditions : Containment design pressure inside closed system Monitored for leaks

Closed System

Class 2 - DBE

Inside Containment

11

FIGURES

1 (e) : Instrument Lines (tubing 19 mm (V4 inch) and smaller)

Instrument •CXr Inside Containment

Class 2 DBE

Systems Closed to the Containment Atmosphere

2 (a) No Isolation Valve

Conditions : Containment design pressure Monitored for leaks

Valve needed only if not_ monitored for leaks

•DKI

Inside Containment

Closed System

Class 6 Class 2

DBE —

2 (b) One Isolation Valve

Conditions : Design pressure > 500 kPa(g) Operates above containment design pressure (124 kPa(g) Monitored for leaks

Inside Containment

ixy Closed System

_DBE alternative

Class 6

DBE -

- 12 -

FIGURES

Systems Connected to the Heat Transport System

3 (a) Open Isolation Valves

CO

Class 6

CX3-

Manual valve operable from control room, or auto closing valve

i L

Class 1

DBE-

Inside Containment

Heat Transport System

(ii)

{X}-

Class 6 -•- Class 1

DBE

•Or

3 (b) Closed Isolation Valves

Class 6 •*- —•- Class 1

• - DBE "J* (alternative)

Inside Containment

Heat Transport System

Inside Containment

Heal Transport System

DBE-

Class6 -*- Class I

— DBE • (alternative)

Of

Inside Containment

Heat Transport System

DBE-

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FIGURES

3 (c) Small Lines (25 mm diameter or less)

Inside Containment

I g H DBE-

Closed System

Class 6 —

N

Heat Transport System

— ^ Class 1

Class 1 or 2

3 (d) Instrument Lines (tubing 19mm *U inch and smaller)

Instrument HXr

Inside Containment

Heat Transport System

Class !

DBE

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APPENDIX B

LIST OF SAFETY DESIGN GUIDES

IDENTIFICATION TITLE

KAEPJ/TR-639/96 KAERI/TR-640/96 KAERI/TR-641/96 KAERI/TR-642/96 KAERI/TR-643/96 KAERI/TR-644/96 KAERI/TR-645/96 KAERI/TR-646/96

Safety Related Systems Seismic Qualification Environmental Qualification Grouping and Separation Fire Protection Containment Extension Radiation Protection Pipe Rupture Protection

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서 지 정 보 양 식

수행겨관보고서 번호 위탁기관보고서 번호 표준보고셔 번호 INIS 주제코드 번호

KAERνTR-644/96

체목 / 부제 CANDU 9 격납건물 확장부의 안전셜계지침

보고서 작성차 몇 부서명 이 득수 (울진5，6호기 기술관리분야) 외 3 인

발행지 대전 발행기관 한국원자력연구소 발행언 1996. 3

패이지 17 도표 유(0) 무( ) 크기 30 x 19

참고사항

비밀여부 공개(0)， 댐외비( ), 급비밀 보고서 종류 기술보고서

위탁연구기관 계약번호

요약 (300단어 내외)

」←--

본 “격납건물 확장부의 안전설계지첨”에는 격납건물의 격리원리와 격납건물 확장부의

요건을 서술하고 었다 금속확장부와 ASME Section III 의 범주에 협는 기기틀은

CAN/CSA-N285.0 과 CAN/CSA- N285.3에 따라 안전등급올 분류하였다. 또한 누설감시능력， 내

진셜계요건 그리고 격납건물확장부의 검사요건등이 본 안전설계지침에 정의되었다. 아울러 배관

계통 관련요건을 포함한 격납건물 격리요건을 규정 요약하여 부록에 표기하였다. 추후 규제기

관의 규제요건， 코드 및 표준의 변경을 지속적으로 추적하여야하며， 본 안전설계지칩도 요건의

변경에 따라 개정되어야 한다.

주제명 키워드 00단어 내외) 격납건물， 확장부， 격리원리， 금속확장부， 누설， 검사요건，

- 16 -

BIBLIOGRAPHIC INFORMATION SHEET

Performing Org.

Report No.

Sponsoring Org. Report No.

Standard Report No. INIS Subject No.

KAERI/TR-644/96

Title/Subtitle Safety Design Guides for Containment Extensions for CANDU 9

Reporter and Department DEUCK SOO LEE (UCN 5&6 Technical Coordination Dept)et al.

Publication Place

Taejon Pub. Org. KAERI Pub.Date 1996. 3

Page 17 Figure and Table Yes(O) No( ) Size 30 x 19

Note

Classified OpenO), Outside( ), ClassC ) Report Type Technical Report

Sponsoring Org.

Contract No.

Abstract (300 words)

This Safety Design Guide for Containment Extension describes the containment isolation philosophy and containment extension requirements. The metal extensions and components falling within the scope of ASME Section III are classified in accordance with the CAN/CSA-N285.0 and CAN/CSA-N285.3. The special consideration for the leak monitoring capability, seismic qualification and inspection requirements for containment extensions, etc., are defined in this design guide. In addition, the containment isolation systems are defined and summarized schematically in appendix A. The change status of the regulatory requirements, code and standards should be traced and this Safety Design Guide shall be updated accordingly.

Subject Keyword (10 words) Containment, Extensions, Isolation Philosophy, Metal Extension, Leak, Inspection Requirements

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