BS 4975:1990

Foreword
Committees responsible
Specification
Section one. General
1.1 Scope
1.2 Definitions
1.3 Basic considerations
1.4 Responsibilities
1.5 Information and requirements to be agreed and to
      be documented
1.6 Interpretation
Section two. Materials
2.1 Concrete
2.2 Reinforcement
2.3 Prestressing system
2.4 Liners (including supported penetration liners)
Section three. Design
3.1 General
3.2 PCPV structure
3.2.1 Design considerations
3.2.2 Analysis for service load conditions
3.2.3 Permissible stresses in concrete and
        reinforcement
3.2.4 Ultimate load analysis
3.3 Liners (including supported penetration liners)
3.3.1 General
3.3.2 Effects of irradiation
3.3.3 Design of liner
3.3.4 Design of ties and shear connectors
3.3.5 Design of corners
3.3.6 Design of penetration liners supported by
        concrete
Section four. Manufacture
4.1 Concrete
4.2 Reinforcement
4.3 Prestressing system
4.4 Liners (including supported penetration liners)
Section five. Inspection and tests
5.1 Concrete
5.2 Reinforcement
5.3 Prestressing system
5.4 Liners (including supported penetration liners)
Section six. Steel closures and unsupported penetrations
6.1 General
6.2 Materials
6.3 Design
6.4 Manufacture
6.5 Monitoring and inspection
6.6 Restrictors
Section seven. Insulation and cooling systems
7.1 General
7.2 Fault analysis
Section eight. Automatic pressure relief devices
8.1 Automatic pressure relief devices
Section nine. Testing and surveillance of completed
structure
9.1 Vessel proof test
9.2 Vessel leak test
9.3 Vessel vacuum test
9.4 Surveillance
Appendices
A. Simplified concepts of the development and analysis
    of stresses in a PCPV
B. Design and methods of analysis
C. Local stresses
D. Design limits for multiaxial compressive stresses in
    concrete
E. Ultimate load conditions
F. Corrosion protection of prestressing tendons
G. Grouting of ducted prestressing tendons
H. Effect of fast neutron irradiation on the properties
J. Effect of fast neutron irradiation on the mechanical
    properties of ferritic steels
K. Recommended practice for assessment of liners
    (including supported penetration liners) subject to
    fatigue
L. Construction of control charts for testing wire,
    strand and bar
M. Optional documentation for supply with the vessel
N. References
Tables
1. Principal compressive field stresses in concrete
2. Permissible stresses in steel reinforcement
Figures
1. Design limits for multiaxial compression
2. Typical fast neutron dose attenuation in a PCPV wall
3. Effect of irradiation on the dimensional changes of
    limestone aggregates, cement paste and a limestone
    aggregate concrete
4. Design fatigue curve for steels for temperatures
    up to and including 375 deg C
5. Construction of test fatigue curve

Design, construction, inspection and testing. Used for shielding and containing gas cooled nuclear reactors and are a form of civil engineering structure requiring particularly high integrity and ensured leak tightness.

1.1.1 This British Standard specifies the design, construction, inspection and testing of prestressed concrete pressure vessels (PCPV) for nuclear reactors, including components that are necessary to maintain the structural integrity and leaktightness of the vessels. However, such concrete pressure vessels are often closely integrated with the operation of the nuclear reactor and its auxiliary plant, and the various parts of the vessel may need to perform functions additional to the structural requirements of this standard.

1.1.2 The safety of concrete pressure vessels depends, firstly, on a correct assessment of the loadings likely to be applied to the vessel and, secondly, on the proper design of the vessel to accept these loadings. This standard covers only the second aspect, the first being the responsibility of the purchaser who has to meet any statutory or other regulations¹⁾.

1.1.3 The safety of concrete pressure vessels throughout their service lives also depends on proper operational procedures being adopted and adequate monitoring and inspection of the vessels during service life being carried out. As operational procedures are the responsibility of the operator they are not included in this standard. Monitoring and inspection are dealt with in 9.4.

1.1.4 Other components of the reactor pressure circuits, including those parts of the ancillary circuits that, for inspection, can be isolated from the primary circuit at any time without having to shut down the reactor, shall comply with the relevant British Standards and any additional requirements specified by the purchaser (see 1.5).

1.1.5 In addition to the definitive requirements, this standard also requires the items detailed in 1.5 to be documented. For compliance with this standard both the definitive requirements and the documented items need to be satisfied.

NOTE 1 Where the words “purchaser” and “manufacturer” occur in the text they should be taken to include representatives of the purchaser and manufacturer or inspectors mutually agreed upon.

NOTE 2 While this standard is based on current British practice which uses PCPVs in association with gas-cooled reactors, it is not intended to limit its use solely to reactors of this type. It is proposed to keep the standard under review, but it is realized that some of the requirements might be inapplicable to new developments and in such cases revised requirements should be specified by the purchaser.

NOTE 3 The titles of the publications referred to in this standard are listed on the inside back cover.

NOTE 4 Bibliographic references are identified by a letter and number in square brackets, e.g. [K4], and will be found either at the end of the relevant appendix or in Appendix N.