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Press releases from the National Radiological Protection Board
Annals of Nuclear Energy~ Vol. 5, pp. 659 to 660. Pergamon Press 1978. Printed in Great Britain
PRESS RELEASES FROM THE NATIONAL RADIOLOGICAL PROTECTION BOARD DISPOSAL OF HIGHLY RADIOACTIVE WASTE IN GEOLOG I C A L FORMATIONS
lead to failure of geologic containment are identified; their probability of occurrence and the means by which activity could then be transported away from the repository are discussed. The main portion of the study is concerned with modelling the release of radioactivity into ground-water, transport of radionuclides through the geosphere and dilution in a freshwater body, followed by calculation of the potential doses to m a n via aquatic terrestrial pathways. Both individual and collective radiation doses are calculated. The hypothetical repository considered in this study contains all the high-level waste which may be produced in the U.K. up to the year 2000. The report recommends substantial investigation into the following:
As part of a series of assessments of the methods available for the disposal of highly radioactive waste from nuclear fuel reprocessing the N R P B has undertaken a preliminary study of the radiological protection aspects of disposal in geological formations. The study has been published today (11 May) as a technical report* and is on sale through HMSO. The study is part of an EEC p r o g r a m m e intended to direct the necessary research and development so that when decisions are needed on the best way to dispose of highly radioactive waste the requisite knowledge on which to base the decision will be available. The main result of this preliminary study is to identify the major areas of uncertainty remaining, most of which will need to be resolved before a final decision can be taken on the acceptability of this method of disposal.
geologic containment failure mechanisms, the behaviour of the vitrified waste under the conditions expected in a repository. the movement of radioactive materials through the geosphere, including the development of better mathematical models, and the acquisition, through researc~ ~f~ better data, e.g. on sorption on deep geologic media. ENVIRONMENTAL
DETAILS
PROTECTION
Highly radioactive waste is an inevitable by-product of nuclear power generation. In the U.K. this waste is stored as a liquid after nuclear fuel has been reprocessed but it is intended to solidify it, probably by vitrification, before disposal. The main practical methods of disposal are emplacement in deep geological formations on land and on or under the ocean floor (last year the N R P B published an assessment of the radiological implications of disposal on the ocean floor~). The new report explains that there are four barriers which can prevent the return of activity to man's environment from a waste repository or can influence the rates at which the return occurs: (i) geologic containment of the waste within the rock formation, (ii) the waste form and its container, Off) retardation of activity during transport through geologic media, and (iv) dispersion and dilution of activity in the biosphere. In the first part of the report the events which could r
* N R P B - R 6 9 - - P r e l i m i n a r y Assessment of the Radiological Protection Aspects of Disposal of High-Level Waste in Geologic Formations by M. D. Hill and P. D. Grimwood ( H M S O £2.00). "l'NRPB-R48--Assessment of the Radiological Protection Aspects of Disposal of High-Level Waste on the Ocean Floor by P. D. Grimwood and G. A. M. Webb. N R P B - R 7 1 - - E n v i r o n m e n t a l Radiation Protection Standards: an Appreciation, by L. D. G. Richings, F. Morley and G. N. Kelly ( H M S O £1.00).
RADIATION STANDARDS
Misunderstanding of the procedural differences in the derivation and application of radiation protection standards in various countries has sometimes led to confusion on this subject during debates on nuclear power. The implication has been that standards in the U.K. are less restrictive than those in use elsewhere. To help to eliminate this misunderstanding the National Radiological Protection Board has today (26 April) published a report:~ which describes the principles involved in setting standards and outlines procedural differences in their derivation and application. The report stresses that the standards in most, if not all, countries are consistent with the system of dose limitation recommended by the International Commission on Radiological Protection and in particular with their principle that radiation doses should be kept "~as low as reasonably achievable". The system is implemented through various procedures which involve judgmerits; some include formal analyses of what is cost-effective. The report outlines the different procedural approaches adopted and the way these lead to different numerical limits published as standards in various countries. These different limits are merely a consequence of different methods of application of the same basic philosophy and do not mean that the actual exposure of people from a given practice will differ between various countries. W h a t is overriding in determining actual exposures is not the numerical limits in standards but the judgment of what is as low as reasonably achievable. Such j u d g m e n t s may differ between countries owing to particular governmental, social and economic conditions. This may produce differences in radiation doses which, however, would be small 659
660
Press release
compared with those sometimes understood to exist merely because of different numerical limits included in standards. Further information is available from the Information Officer, NRPB, Harwell, Didcot, Oxon, OXI 1 0 R Q , Tel.: Rowstock (023 583) 600 Ext. 410.
AIR S A M P L I N G I N C U M B R I A The National Radiological Protection Board is to undertake a programme of air sampling to collect data to enable it to determine radiation doses to the public in Cumbria from airborne radioactive material. The study is part of the NRPB's function of keeping under review the radiation exposure of the public from all sources of radiation; this is a subject on which the NRPB publishes periodic reports. The NRPB's sampling operation will last for 6 months starting in mid-June; samples will be taken at five points around Windscale. The objectives of the study are to measure the concentrations of actinides and fission products in the air and to assess the influence of environmental factors such as weather conditions on these concentrations. Standard high volume air sampling equipment will be used. Any radioactive material in the air samples will be
collected on filter paper, which the NRPB will send to its own laboratories for analysis. The NRPB will publish the results of the study in due course. In September 1977, during the Windscale Inquiry, the NRPB carried out air sampling at Ravenglass at the request of the Inspector; it detected levels of airborne activity which, if maintained for long periods of time, would have led to radiation doses to the public well below the internationally recommended limits for members of the public. Other sources of radiation doses to the public
The NRPB also has the following investigations in hand: A programme of air and water sampling for radioactive fallout from weapons tests, to assess doses to the public from this source. A study of radiation doses from exposure to the naturally occurring radioactive gas, radon, in homes. An investigation of the radiation doses to the public from the diagnostic use of X-rays; the investigation includes the collection of data on X-ray examinations at about 100 hospitals. Further information: Information Officer, NRPB, tel: Rowstock (023 583) 600 ext. 410.
PRESS RELEASES FROM THE NATIONAL RADIOLOGICAL PROTECTION BOARD DISPOSAL OF HIGHLY RADIOACTIVE WASTE IN GEOLOG I C A L FORMATIONS
lead to failure of geologic containment are identified; their probability of occurrence and the means by which activity could then be transported away from the repository are discussed. The main portion of the study is concerned with modelling the release of radioactivity into ground-water, transport of radionuclides through the geosphere and dilution in a freshwater body, followed by calculation of the potential doses to m a n via aquatic terrestrial pathways. Both individual and collective radiation doses are calculated. The hypothetical repository considered in this study contains all the high-level waste which may be produced in the U.K. up to the year 2000. The report recommends substantial investigation into the following:
As part of a series of assessments of the methods available for the disposal of highly radioactive waste from nuclear fuel reprocessing the N R P B has undertaken a preliminary study of the radiological protection aspects of disposal in geological formations. The study has been published today (11 May) as a technical report* and is on sale through HMSO. The study is part of an EEC p r o g r a m m e intended to direct the necessary research and development so that when decisions are needed on the best way to dispose of highly radioactive waste the requisite knowledge on which to base the decision will be available. The main result of this preliminary study is to identify the major areas of uncertainty remaining, most of which will need to be resolved before a final decision can be taken on the acceptability of this method of disposal.
geologic containment failure mechanisms, the behaviour of the vitrified waste under the conditions expected in a repository. the movement of radioactive materials through the geosphere, including the development of better mathematical models, and the acquisition, through researc~ ~f~ better data, e.g. on sorption on deep geologic media. ENVIRONMENTAL
DETAILS
PROTECTION
Highly radioactive waste is an inevitable by-product of nuclear power generation. In the U.K. this waste is stored as a liquid after nuclear fuel has been reprocessed but it is intended to solidify it, probably by vitrification, before disposal. The main practical methods of disposal are emplacement in deep geological formations on land and on or under the ocean floor (last year the N R P B published an assessment of the radiological implications of disposal on the ocean floor~). The new report explains that there are four barriers which can prevent the return of activity to man's environment from a waste repository or can influence the rates at which the return occurs: (i) geologic containment of the waste within the rock formation, (ii) the waste form and its container, Off) retardation of activity during transport through geologic media, and (iv) dispersion and dilution of activity in the biosphere. In the first part of the report the events which could r
* N R P B - R 6 9 - - P r e l i m i n a r y Assessment of the Radiological Protection Aspects of Disposal of High-Level Waste in Geologic Formations by M. D. Hill and P. D. Grimwood ( H M S O £2.00). "l'NRPB-R48--Assessment of the Radiological Protection Aspects of Disposal of High-Level Waste on the Ocean Floor by P. D. Grimwood and G. A. M. Webb. N R P B - R 7 1 - - E n v i r o n m e n t a l Radiation Protection Standards: an Appreciation, by L. D. G. Richings, F. Morley and G. N. Kelly ( H M S O £1.00).
RADIATION STANDARDS
Misunderstanding of the procedural differences in the derivation and application of radiation protection standards in various countries has sometimes led to confusion on this subject during debates on nuclear power. The implication has been that standards in the U.K. are less restrictive than those in use elsewhere. To help to eliminate this misunderstanding the National Radiological Protection Board has today (26 April) published a report:~ which describes the principles involved in setting standards and outlines procedural differences in their derivation and application. The report stresses that the standards in most, if not all, countries are consistent with the system of dose limitation recommended by the International Commission on Radiological Protection and in particular with their principle that radiation doses should be kept "~as low as reasonably achievable". The system is implemented through various procedures which involve judgmerits; some include formal analyses of what is cost-effective. The report outlines the different procedural approaches adopted and the way these lead to different numerical limits published as standards in various countries. These different limits are merely a consequence of different methods of application of the same basic philosophy and do not mean that the actual exposure of people from a given practice will differ between various countries. W h a t is overriding in determining actual exposures is not the numerical limits in standards but the judgment of what is as low as reasonably achievable. Such j u d g m e n t s may differ between countries owing to particular governmental, social and economic conditions. This may produce differences in radiation doses which, however, would be small 659
660
Press release
compared with those sometimes understood to exist merely because of different numerical limits included in standards. Further information is available from the Information Officer, NRPB, Harwell, Didcot, Oxon, OXI 1 0 R Q , Tel.: Rowstock (023 583) 600 Ext. 410.
AIR S A M P L I N G I N C U M B R I A The National Radiological Protection Board is to undertake a programme of air sampling to collect data to enable it to determine radiation doses to the public in Cumbria from airborne radioactive material. The study is part of the NRPB's function of keeping under review the radiation exposure of the public from all sources of radiation; this is a subject on which the NRPB publishes periodic reports. The NRPB's sampling operation will last for 6 months starting in mid-June; samples will be taken at five points around Windscale. The objectives of the study are to measure the concentrations of actinides and fission products in the air and to assess the influence of environmental factors such as weather conditions on these concentrations. Standard high volume air sampling equipment will be used. Any radioactive material in the air samples will be
collected on filter paper, which the NRPB will send to its own laboratories for analysis. The NRPB will publish the results of the study in due course. In September 1977, during the Windscale Inquiry, the NRPB carried out air sampling at Ravenglass at the request of the Inspector; it detected levels of airborne activity which, if maintained for long periods of time, would have led to radiation doses to the public well below the internationally recommended limits for members of the public. Other sources of radiation doses to the public
The NRPB also has the following investigations in hand: A programme of air and water sampling for radioactive fallout from weapons tests, to assess doses to the public from this source. A study of radiation doses from exposure to the naturally occurring radioactive gas, radon, in homes. An investigation of the radiation doses to the public from the diagnostic use of X-rays; the investigation includes the collection of data on X-ray examinations at about 100 hospitals. Further information: Information Officer, NRPB, tel: Rowstock (023 583) 600 ext. 410.