MINIMIZATION AND SEGREGATION OF RADIOACTIVE WASTES IAEA, VIENNA, 1992 IAEA-TECDOC-652 ISSN

Transcription

1 IAEA-TECDOC-652 Minimization

2 The IAEA does

3 MINIMIZATION AND SEGREGATION OF RADIOACTIVE WASTES IAEA, VIENNA, 1992 IAEA-TECDOC-652 ISSN Printed

4 FOREWORD

5 Treatment and Conditioning of Spent Ion Exchange Resins from Research Reactors, Precipitation Sludges

6 CONTENTS 1. INTRODUCTION Background Objectives Scope...

7 6. SEGREGATION OF WASTE General considerations...

8 1. INTRODUCTION 1.1. Background Radioactive wastes are generated by virtually all activities which utilize radioactive materials

9 MINIMIZATION

10 objectives, a further objective, i.e. becomes greatly important segregation or sorting of wastes

11 Management of spent sealed sources has specifically been covered in a previous manual [2]..Conditioned sealed sources must

12 There

13 Requirements

14 storage. Some of the options initially considered may be discarded for non-radiation protection reasons, for example, purely on grounds of costs or

15 TABLE II GENERAL CHARACTERISTICS OF WASTE CATEGORIES WITH REGARD TO DISPOSAL [13] Waste category Important features

16 alpha-emitters

17 TABLE

18 emulsifying ability density - viscosity surface tension.

19 other materials that react with water to evolve heat and flammable gases, e.g. hydrides, nitrides, carbides etc. The risk of fire or explosion is particularly important also during solid waste compaction. Aluminium capsules are commonly used for isotope target containment. However, aluminium reacts with alkalis (including the alkali in fresh cement grout)

20 activities. All may generate radioactive waste, with the type and volume of waste depending on the research conducted. Research activities may be carried out either in small laboratories or in a full nuclear research centre. The nature of the contamination and the type of waste generated at a research centre depend upon the research programme and can vary widely. The main wastes generated by the operation of a low power research reactor are the liquid wastes, ion exchange resins, irradiated equipment and general trash Production of radioisotopes The research reactor is assumed to provide the irradiation facility for producing some radioisotopes particularly the short lived nuclides 32 P, 35 S) 75 Sej 99m Tc Particle accelerators (including cyclotrons) may be also used to produce by bombardment of targets isotopes such as ^0, 1%. Ü-C and mostly for positron emission tomography and ^-^1, ^^In, 201^1, 67g

21 Application

22 Miscellaneous techniques Static elimination Smoke detectors Lightning warning systems Dewpoint meters Nuclear batteries Inadvertent concentration of radioactivity Inadvertent production of X rays.

23 TABLE VI WASTES ARISING FROM MEDICAL, INDUSTRIAL, RESEARCH AND TRAINING ACTIVITIES Type

24 Typical distribution of solid wastes generated in research centres is as follows:

25 4.2. Legislation and regulations Waste management legislation should

26 The regulatory body needs, and must have, financial resources in order to function effectively

27

28 5.1. Source reduction Source reduction,

29 or licensing bodies

30 Containment

31 Design should include a schedule for the inspection and monitoring-of secondary containment

32 This individual can be called Radioactive-Materials Co-ordinator (RMC) with functions outlined in [9] and summarized in Annex II. The officer should be responsible for all procedures and operations involving the use of radioactive materials

33 Strong plastic bags should be used to prevent double bagging of waste materials

34 the high activity 13?cs and *>0co sources. Transfer of sources to other users within the national boundaries of the country offers economic advantages in both source procurement and waste disposal. Return to the original supplier. Radioactivity contained in the spent sources may be recovered for incorporation in new sources. Many institutions in different countries routinely refurbish spent sources for economic reasons. Reuse of decontaminated materials. Nuclear facilities usually contain considerable quantities of expensive material that have been contaminated but not activated. Much of this material has significant value if it can be sufficiently decontaminated to permit its unrestricted use. A number of methods are available as decontamination techniques [23, 24]. The choice of reuse or disposal of contaminated materials and equipment will depend upon realistic cost/benefit and radiation detriment analysis and the requirements of national regulations. Additional waste minimization could be provided by reuse decontamination solutions and recycle clarified liquors within a process to reduce fresh water additions and volumes of effluent for treatment Waste treatment Waste treatment comprises of operations intended to benefit safety or economy by changing the characteristics of the waste. Three basic treatment concepts are: - volume reduction; removal of radionuclides from the waste; change of composition. Considerable experience has been accumulated in the satisfactory treatment of the wastes [20,21], Other technical manuals [25-27] describe in detail methods and equipment for treatment of radioactive waste arising in a developing country without nuclear power. 6. SEGREGATION OF WASTE 6.1. General considerations In order to facilitate their subsequent handling, treatment and disposal, it is necessary to segregate wastes at the point of origin according to their chemical, physical, biological and radiological properties. The objectives of waste segregation are: - Remove non-radioactive material or components from radioactive waste; - Separate waste into appropriate categories (see Section 2); - Recover valuable materials for recycling and recycle wastes into the process. This segregation will produce a number of direct benefits, e.g. segregation of non-radioactive waste from radioactive waste at the source 35

35 will significantly reduce the volume of radioactive waste requiring storage or further treatment;, segregation

36 6.2. Solid wastes Monitoring If possible, solid wastes should be monitored at the point of generation, depending

37 versatile economic

38 FIG. 4. Sorting operations in the sealed area. 39

39 LABORATORY SGAE SEIBERSDORF AB BB FS (Outi-sluice Concrete Sealing Compartment Sluice

40 Documentation

41 TABLE

42 Acidic and alkaline wastes are best stored separately from each other. It is quite likely that because of the inactive ions present in the liquids precipitation

43 7. CONCLUSIONS This report has outlined some techniques for treatment of radioactive wastes that are quite distinct from those associated with the nuclear fuel cycle. Quantities of radioactive waste are small and their subsequent treatment and disposal is uncomplicated. Simple options for segregation of radioactive wastes undertaken

44 (Reproduced from Annex Annex I

45 Solid wastes

46 Appendix

47 TABLE Al. ALI min VALUES FOR SOME COMMON RADIONUCLIDES Nuclide

48 Annex

49 REFERENCES [1] INTERNATIONAL ATOMIC ENERGY AGENCY, Design and Operation of Off-Gas Cleaning and Ventilation Systems in Facilities Handling Low and Intermediate Level Radioactive Material, Technical Reports Series No. 292, IAEA, Vienna (1988). [2] INTERNATIONAL ATOMIC ENERGY AGENCY, Handling, Conditioning and Disposal of Spent Sealed Sources, IAEA-TECDOC-548, IAEA, Vienna (1990). [3] INTERNATIONAL ATOMIC ENERGY AGENCY, Regulations for the Safe Transport of Radioactive Material, 1985 Edition (As Amended 1990), Safety Series

50 [14] INTERNATIONAL ATOMIC ENERGY AGENCY, Criteria for Underground Disposal

51 [28] HOLT,