Safety_Series_015_1965 - gnssn - International Atomic Energy ...

This publication is not longer validPlease see http://www-ns.iaea.org/standards/C oncrete pipes installed vertica lly in the ground.F u e l-ro d storage h oles are sim ila r except that the extern al 6 0 -cmpipe contains a co n ce n tric 15- o r 2 5 -c m -d ia m . s te e l p ip e. Theannulus is fille d with con crete and the pipe capped either with con ­crete or a rem ovable steel plug accord in g to whether the storage ispermanent or tem porary. Testing has shown that when fuel elements,aged fo r 6 m onths, are p laced in side, heat d issip a tion to the s u r ­rounding d ry sand is sa tis fa cto ry and the tem p era tu re r is e in theco n cre te p ip es is a ccep tably low .Both liquid and solid disposals to the ground have been practisedrou tin ely at Oak R idge, T en n essee, fo r m any y e a r s . R adioactiveeffluents w ere disch arged fo r 10 y ea rs into three open pits each of4X106 litr e s ca p acity, .a ccom m od a tin g a total d a ily in flow o f2. 8X104 litres [2], The m ore hazardous radiocations have been r e ­tained in the Conasauga shale and investigations have shown that thereis no apparent danger of stron tiu m -90 seeping into nearby stream s.H ow ever, ru th eniu m -106 experien ced no such retention and appearedin a stream after 5-15 days fro m one pit and after 150-30081