1、= -ANSI/ANs-55.4-1993 gaseous radioactive waste processing systems for light water reactor plants This standard has been reviewed and reaffirmed by the ANS Nuclear Facilities Standards Committee (NFSC) with the recognition that it may reference other standards and documents that may have been superc
2、eded or withdrawn. The requirements of this document will be met by using the version of the standards and documents referenced herein. It is the responsibility of the user to review each of the references and to determine whether the use of the original references or more recent versions is appropr
3、iate for the facility. Variations from the standards and documents referenced in this standard should be evaluated and documented. This standard does not necessarily reflect recent industry initiatives for risk informed decision-making or a graded approach to quality assurance. Users should consider
4、 the use of these industry initiatives in the application of this standard. This standard has been reviewed and reaffirmed by the ANS Nuclear Facilities Standards Committee (NFSC) with the recognition that it may reference other standards and documents that may have been superceded or withdrawn. The
5、 requirements of this document will be met by using the version of the standards and documents referenced herein. It is the responsibility of the user to review each of the references and to determine whether the use of the original references or more recent versions is appropriate for the facility.
6、 Variations from the standards and documents referenced in this standard should be evaluated and documented. This standard does not necessarily reflect recent industry initiatives for risk informed decision-making or a graded approach to quality assurance. Users should consider the use of these indu
7、stry initiatives in the application of this standard. ANSVANS-55.4-1993 American National Standard for Gaseous Radioactive Waste Processing Systems for Light Water Reactor Plants Secretariat American Nuclear Society Prepared by the American Nuclear Society Standards Committee Working Group ANS-55.4
8、Published by the American Nuclear Society 555 North Kensington Avenue La Grange Park, Illinois 60525 USA Approved July 16, 1993 by the American National Standards Institute, Inc. American National Standard Designation of this document as an American National Standard attests that the principles of o
9、penness and due process have been followed in the approval procedure and that a consensus of those directly and materially affected by the standard has been achieved. This standard was developed under the procedures of the Standards Committee of the American Nuclear Society; these procedures are acc
10、redited by the American National Standards Institute, Inc., as meeting the criteria for American National Standards. The consensus committee that approved the standard was balanced to ensure that competent, concerned, and varied interests have had an opportunity to participate. An American National
11、Standard is intended to aid industry, consumers, govern mental agencies, and general interest groups. Its use is entirely voluntary. The existence of an American National Standard, in and of itself, does not preclude anyone from manufacturing, marketing, purchasing, or using products, processes, or
12、procedures not conforming to the standard. By publication of this standard, the American Nuclear Society does not insure anyone utilizing the standard against liability allegedly arising from or after its use. The content of this standard reflects acceptable practice at the time of its approval and
13、publication. Changes, if any, occurring through developments in the state of the art, may be considered at the time that the standard is subjected to periodic review. It may be reaffirmed, revised, or withdrawn at any time in accordance with established procedures. Users of this standard are caution
14、ed to determine the validity of copies in their possession and to establish that they are of the latest issue. The American Nuclear Society accepts no responsibility for interpretations of this standard made by any individual or by any ad hoc group of individuals. Requests for interpretation should
15、be sent to the Standards Department at Society Headquarters. Action will be taken to provide appropriate response in accordance with established procedures that ensure consensus on the interpretation. Comments on this standard are encouraged and should be sent to Society Headquarters. Published by A
16、merican Nuclear Society 555 North Kensington Avenue, La Grange Park, Illinois 60525 USA Copyright 1994 by American Nuclear Society. Any part of this standard may be quoted. Credit lines should read “Extracted from American National Standard ANSI/ANS-55.4-1993 with permission of the publisher, the Am
17、erican Nuclear Society.“ Reproduction prohibited under copyright convention unless written permission is granted by the American Nuclear Society. Printed in the United States of America Foreword (This foreword is not a part of American National Standard for Gaseous Radioactive Waste Processing Syste
18、ms for Light Water Reactor Plants, ANSI/ANS-55.4-1993, but is included for information purposes only.) Management of the gaseous radioactive waste generated as a by-product of nuclear power plant operation constitutes a major management responsibility. Quantities of gaseous radioactive waste generat
19、ed during operation are dependent upon several factors including design conditions, type of equipment, equipment arrangements, and operating philosophy. The purpose of this standard is to establish uniform practices and rmmmum requirements for design, construction, and performance, with due consider
20、ation for operation, of gaseous radioactive waste processing systems. The standard sets forth design, construction, and performance requirements for acceptable gaseous radioactive waste processing systems. Adherence by system designers to the criteria contained in the standard will enable the operat
21、or (a) to control to regulatory levels radiation exposures to operating personnel; (b) to assure a low probability of unplanned release of radioactivity from the system; and (cto control system releases of radioactivity to levels as low as reasonably achievable. In accordance with ANS policy to main
22、tain standards on a five year basis, the standard was revised to update its contents and to reflect changes in industry practices. Members ofWorking Group 55.4, and their affiliations at the time of their approval of this standard, were as follows: F. W. Hartley, Chairman, Management Analysis Compan
23、y J. A. Battaglia, Westinghouse Electric Corporation D. H. DaCosta, Ergenics, Incorporated S. A. Lamanna, The Babcock the word “should“ to denote a recommendation; and the word “may“ to denote permission, neither a requirement nor a recommendation. standard cubic foot (SCF). As used in this standard
24、, an amount of gas occupying one cubic foot at a temperature of 60“F and a pressure of one atmosphere (absolute). 3. Criteria This standard establishes nummum require ments for the design and construction of the GRWPS to achieve the performance, safety, and operational objectives specified in this s
25、ection. 1 American National Standard ANSI/ANS-55.4-1993 3.1 Performance Criteria. The GRWPS shall be designed such that radioactive materials in gaseous effiuents from the plant collectively meet the design objectives given in: (a) Title 10, “Energy,“ Code of Federal Regula tions, Part 50, “Domestic
26、 Licensing of Production and Utilization Facilities,“ (10 CFR 50) Appendix I, “Numerical Guides for Design Objectives and Limiting Conditions for Operation to Meet the Criterion As Low as is Reasonably Achievable for Radioactive Material in Light-Water-Cooled Nuclear Power Reactor Effiuents“ 3. (b)
27、Title 10, “Energy,“ Code of Federal Regula tions, Part 50, “Domestic Licensing of Production and Utilization Facilities,“ Section 50.34a 4. (c) Title 10, “Energy,“ Code of Federal Regula tions, Part 20, “Standards for Protection Against Radiation“ (10 CFR 20) 5. (d) Title 10, “Energy,“ Code of Feder
28、al Regu lations, Part 50, “Domestic Licensing of Produc tion and Utilization Facilities,“ Appendix A, “General Design Criteria for Nuclear Power Plants,“ Criteria 60 and 64 6. 3.2 Safety Criteria. The GRWPS shall be de signed such that the release of radioactive mate rial to the environment or expos
29、ure to the general public does not exceed the requirements of 10 CFR 20 5, nor a small fraction of the guidelines con tained in Title 10, “Energy,“ Code of Federal Regulations, Part 100, “Reactor Site Criteria“ 7. 3.3 Operational Criteria. The design, construc tion, and operation of the GRWPS shall
30、be such that radiation exposures to operating and main tenance personnel are maintained “as low as is reasonably achievable“ (ALARA) in accordance with 10 CFR 50, Appendix I 3. 4. Design Requirements 4.1 Code Classification. Equipment and piping shall be designed, constructed, and tested in accordan
31、ce with the requirements of the appli cable codes as given in Table 1. 4.2 Seismic Design. Supports for equipment that by design are used for the storage of gaseous radioactive waste for decay, and portions of struc tures housing this equipment, shall be designed to withstand the effect of an operat
32、ing basis earth quake (OBE). For the systems normally operating at pressures greater than 1.5 atmospheres (abso lute), the requirement for OBE seismic design shall apply to isolation valves, equipment, inter-2 connecting piping, and components located be tween the upstream and downstream valves used
33、 to isolate these components from the rest of the system (e.g., waste gas storage tanks in a PWR). For systems that operate essentially at atmospher ic pressure and retain gases on charcoal adsorbers, only the equipment supports and portions of structures housing the tanks shall be designed to these
34、 seismic design criteria (e.g., charcoal delay tanks in a BWR). 4.3 Quality Assurance. The design, procure ment, fabrication, and construction activities shall conform to the quality assurance provisions of the codes and standards specified in Table 1. In addi tion, or where not covered by the refer
35、enced codes and standards, the following quality assurance features shall be established as a minimum. 4.3.1 System Designer and Procurer. 4.3.1.1 Design and Procurement Docu ment Control. Design and procurement docu ments shall be verified for conformance to the requirements of this standard by ind
36、ividual(s) within the design organization who are not the originators of the document. Changes to these documents shall be verified or controlled to main tain conformance to this standard. 4.3.1.2 Control of Purchased Material, Equipment, and Services. Measures shall be established to ensure that su
37、ppliers of material, equipment, and construction services are capable of supplying these items to the quality specified in the procurement documents. This may be done by an evaluation of a survey of the suppliers products and facilities. 4.3.1.3 Handling, Storage, and Shipping. Instructions shall be
38、 provided in procurement documents to control the handling, storage, ship ping, and preservation of material and equipment to prevent damage, deterioration, and reduction of cleanliness. 4.3.2 System Fabricator and Constructor. 4.3.2.1 Inspection. In addition to required code instructions, a program
39、 for inspection of con struction and installation quality related activities shall be established and executed by, or for, the organization performing the activity to verify conformance with the documented instructions, procedures, and drawings. This shall include the visual inspection of components
40、 prior to instal lation for conformance with procurement docu ments, and visual inspection of items and systems following installation, cleaning, and passivation (where applied). 4.3.2.2 Inspection, Test, and Operating Status. Measures shall be established to provide for the identification of items
41、which have satis factorily passed the required inspections and tests. 4.3.2.3 Identification and Corrective Action for Items of Nonconformance. Mea sures shall be established to identify items of nonconformance with regard to the requirements of the procurement documents or applicble codes and stand
42、ards and to identify the remedial action taken to correct such items. 4.4 Materials. Materials for pressure retaining components of process systems shall be selected from those covered by the material specifications listed in Table 1, except that malleable, wrought, or cast iron materials shall not
43、be used. The components shall meet all of the mandatory requirements and the material specifications with regard to manufacture, examination, repair, testing, identification, and certification. (a) For equipment, other than piping and valves, with operating temperatures less than 32“F, material shal
44、l meet the test requirements of Paragraph PG-84, American National Standard ANSIIASME Boiler and Pressure Vessel Code (B refer to American National Standard for Sampling Line Piping and Tubing Standards for Use in Nuclear Power Plants, ANSIIISA-S67.10-1986 9. 4. 7 Design for Explosive Conditions. If
45、 the potential for an explosive mixture of hydrogen and oxygen exists, the gaseous waste handling and treatment system shall be designed either to withstand the effects of a hydrogen explosion or be provided with two independent gas analyzers to detect the presence of flammable mixtures and to annun
46、ciate both locally and in the main control room. Catalytic recombiner outlet piping shall not be interconnected with those piping regions which, by design, contain explosive mixtures. Additional ly, the following are examples of features which should be used to reduce the probability of explosion: (
47、a) Maintenance of non-explosive mixture. (b) Minimization of potential ignition sources. (c) System and component purging to assure non-explosive mixtures prior to inspection and maintenance. (d) Purging of standby equipment. (e) Adequate room ventilation for areas con taining gaseous radwaste equip
48、ment. (f) No backflow of off-gas through the re .combiner during idle periods (catalyst mi gration). (g) No branching of shared gaseous auxiliary supply lines to points both upstream and 3 American National Standard ANSI/ANS-55.4-1993 downstream of recombiner. (h) Recombination of H.! with 02 to lim
49、it hydro gen to 1% by volume. (i) Administrative controls and procedures to assure that features such as those above are enforced. 4.8 Provisions for Calibration and Testing. The GRWPS shall be designed to allow for the periodic calibration of instrumentation. For those systems which are not in continuous operation, testing provisions shall be incorporated into the system design to enable periodic re-evaluation of the operability and functional performance of all active components in the syst
