Safety_Series_041_1975 - gnssn - International Atomic Energy ...

More documents

Recommendations

Info

This publication is no longer valid Please see http://www.ns-iaea.org/standards/ TABLE X. EXPOSURE PATHWAYS FOR DISCHARGES FROM SELECTED CEGB NUCLEAR POWER STATIONS 05 o T y p ic a l ex p osu re S tation and c r it ic a l m a te ria l E xposed p o p u la tio n grou p D a ily con su m p tion rate or annual hours o f exposure E xposed organ Im p orta n t r a d io n u clid e s D eriv ed w ork in g lim it o f the p o p u la tio n grou p co n c e rn e d P ercen ta g e o f ICRP dose lim it (m r e m /a ) B radw el] Oyster O y ster fish erm en 75 g /d T o ta l body 65Z n (c r itic a l) 29 0 0 p C i/g 0 . 3
This publication is no longer valid Please see http://www.ns-iaea.org/standards/ APPENDIX III 61 No contribution to gonad dose from nuclear power stations exceeds a few man* rem s as an annual total. The total annual dose to the critical group of 100 anglers at Trawsfynydd, whose whole - body dose due to consumption of fish contaminated with 137Cs and Cs is estimated to be about 20 m rem /a (Table X), is a 2 man •rem s. The other stations in Table X contributed less than 0.1 man •rem s between them. It is possible that sm aller doses to larger populations nearby might contribute a few additional man •rem s per station. Exposure factors involved in the discharge of aqueous radioactive wastes from additional CEGB power stations are listed in Table XI and estimates of the radiation doses received by the population are given in Table XII. Doses from UKAEA discharges Upper limits to annual doses arising from radioactive liquid and gaseous waste discharges can be deduced from measured activities when expressed as percentages of DWLs in environmental materials. Most values do not exceed a few per cent and many are well below 1% of the DWL. The only values that regularly exceed 10% are due to 106Ru in liquid discharges to sea from Windscale in Cumberland. Many aspects of the critical pathway have been extensively studied by Preston and Jefferies, who carried out surveys in distribution and consumption of laverbread during the years 1962-1967 and concluded that the average exposure of the critical group concerned (100 persons out of a total of some 26 000 laverbread eaters) was about 600 m rem /a to the GI tract compared with the dose lim it of 1500 m rem /a. This was estimated on the conservative assumption that these exceptional consum ers regularly eat laverbread manufactured solely from Cumberland seaweed, whereas an average market dilution factor of 4.2, due to the in corporation of non-Cumberland seaweed, operated during the period of sampling. Other exposure pathways arising as a result of Windscale discharges are external radiation of fishermen from contaminated estuarine silt and fishing gear, and internal radiation of fishermen who eat locally caught fish. Table XIII gives parameters of interest for all four pathways and estimated exposures to the very limited numbers of persons (10 or 100) in each critical group. The most important group next to laverbread consum ers are fishermen who spend about 350 hours per year on estuarine silt and are estimated to receive 50 m rem /a whole-body radiation.
Page 1 and 2:
This publication is no longer valid
Page 3 and 4:
Page 5 and 6:
Page 7 and 8:
Page 9 and 10:
Page 11 and 12:
Page 13 and 14:
Page 15 and 16:
Page 17 and 18:
Page 19 and 20:
Page 21 and 22:
Page 23 and 24: This publication is no longer valid
Page 59 and 60: 1M|137CJ g 1 litre 134Cs C 3 .5 lit
Page 73: This publication is no longer valid
Page 101 and 102: T A B L E X V I (con t.) This publi
Page 109 and 110: T A B L E X V III (con t.) This pub
Page 113 and 114: T A B L E X X (con t.) This publica
Page 125 and 126:
Page 127 and 128:
Page 129 and 130:
Page 131 and 132:
Page 133 and 134:
Page 135 and 136:
Page 137 and 138:
Page 139 and 140:
Page 141 and 142:
Page 143 and 144:
Page 145 and 146:
Page 147 and 148:
show all

Safety_Series_041_1975 - gnssn - International Atomic Energy ...

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?