12 Operating Experience with the Tritium and Hydrogen Extraction Plant at the Laue—Langevin Institute PH.
PAUTROT
Institute Max Von Laue-Paul Langevin, 38000, Grenoble, France
Downloaded by UNIV OF PITTSBURGH on May 4, 2015 | http://pubs.acs.org Publication Date: June 1, 1978 | doi: 10.1021/bk-1978-0068.ch012
M. DAMIANI Sulzer Brothers L t d . , Dept. 6162, CH-8401 Winterthur, Switzerland
The I n s t i t u t e Max Von LAUE - P a u l LANGEVIN in GRENOBLE is a s o c i e t y founded in 1967 by a government agreement between FRANCE and GERMANY. In 1974 GREAT BRITAIN a l s o j o i n e d the I n s t i t u t e . The I n s t i t u t e o p e r a t e s the High F l u x R e a c t o r whose purpose is a l a r g e programme of n u c l e a r p h y s i c s r e s e a r c h u s i n g the n e u t r o n s produced by the r e a c t o r . T h i s High F l u x R e a c t o r has a t h e r m a l performance of 57 MW w i t h a s i n g l e heavy water c o o l e d and moderated circuit. Heavy water h o l d - u p is about 40 m . The mean f l u x of t h e r m a l n e u t r o n s in the heavy water is e q u a l t o 1,8 . 10 n / c m s e c , which l e a d s t o f o r m a t i o n of tritium w i t h a s a t u r a t i o n activity of more than 80 C u r i e per litre ( a f t e r 10 y e a r s about 30 Curie/1). T h i s is s i m i l a r t o the v a l u e e x p e c t e d in the moderator circuit of the CANDU type r e a c t o r . For s a f e t y r e a s o n s , tritium c o n c e n t r a t i o n in heavy water s h o u l d not exceed 3 C u r i e per litre and in o r d e r t o m a i n t a i n moderator efficiency of heavy w a t e r , its fractional c o n c e n t r a t i o n s h o u l d not be lower than 99,6 mol %. The installation fulfilling the mentioned d u t i e s was built by CCM/SULZER* in c l o s e c o - o p e r a t i o n w i t h the C.E.A. (Commissariat ā l'Energie A t o m i q u e ) . SULZER a l r e a d y had e x p e r i e n c e in the low temperature distillation of hydrogen from a s m a l l heavy water p l a n t in EMS S w i t z e r l a n d . The installation a t the LAUE-LANGEVIN I n s t i t u t e on the Grenoble N u c l e a r C e n t r e site is the first known p l a n t in o p e r a t i o n f o r the s i m u l t a n e o u s e x t r a c t i o n of hydrogen and tritium from heavy w a t e r . 3
14
*
is L i c e n s e e process
of
©
2
a patent
owned by the CEA for t h i s
0-8412-0420-9/78/47-068-163$05.00/0
In Separation of Hydrogen Isotopes; Rae, H.; ACS Symposium Series; American Chemical Society: Washington, DC, 1978.
164
SEPARATION OF HYDROGEN ISOTOPES
Design Data. - T r i t i u m c o n c e n t r a t i o n of heavy water has t o be s t a b i l i z e d a t 1,7 C i / 1 by an annual e x t r a c t i o n of 160 000 C u r i e , e q u i v a l e n t t o about 60 N l of pure t r i t i u m . - C o n t e n t of heavy water has t o be m a i n t a i n e d a t 99,6 mol % by an a n n u a l e x t r a c t i o n of 160 l i t r e s of l i g h t water, e q u i v a l e n t t o about 2 00 Nm of hydrogen.
Downloaded by UNIV OF PITTSBURGH on May 4, 2015 | http://pubs.acs.org Publication Date: June 1, 1978 | doi: 10.1021/bk-1978-0068.ch012
3
P r i n c i p l e of O p e r a t i o n . F i g u r e 1 shows the mass f l o w s w i t h the c o r r e s p o n d i n g c o n t e n t s a t normal opera t i o n c o n d i t i o n s in 1976, and f u r t h e r m o r e , t h a t the p l a n t is made up of two main p a r t s : 1.
C a t a l y t i c exchange between heavy water vapour and d e u t e r i u m gas a t 200°C and about 1,2 b a r , which a l l o w s the mass t r a n s f e r of hydrogen and t r i t i u m from heavy water t o d e u t e r i u m t o r e a c h e q u i l i b r i u m a c c o r d i n g t o the f o l l o w i n g r e a c t i o n s :
HDO
+ D2
D2O
+
HD
2.
Low temperature r e c t i f i c a t i o n of the hydrogen i s o t o p e s HD/D2/DT/T2 a t about 1,5 bar in two columns w i t h e x t r a c t i o n of HD a t the top of the f i r s t column and pure t r i t i u m a t the bottom of the second column. The f l o w s h e e t F i g . 2 shows t h a t the heavy water coming from the r e a c t o r is e v a p o r a t e d , s u p e r h e a t e d , and mixed w i t h the d e u t e r i u m t o pass through the c a t a l y t i c r e a c t o r where the i s o t o p i c exchange r e a c t i o n s o c c u r ; it is then recondensed t o be s e p a r a t e d from the d e u t e r i u m and t r a n s f e r r e d t o the second and then t o the t h i r d s t a g e of the c a t a l y t i c exchange. The d e u t e r i u m coming out of the c a t a l y t i c exchange is d r i e d and p u r i f i e d b e f o r e b e i n g s e n t i n t o a d i s t i l l a t i o n column c o n t a i n i n g S u l z e r p a c k i n g s . The p a r t i a l l y t r i t i u m and hydrogen s t r i p p e d d e u t e r i u m coming out of the column r e t u r n s t o the c a t a l y t i c exchange t h r o u g h an e x p a n s i o n v e s s e l . The d e u t e r i u m h y d r i d e drawn o f f w i t h a c o n t e n t of about 80 mol % a t the head is s e n t to a burner. The t r i t i a t e d d e u t e r i u m a t the f o o t of the column is s e n t t o a second column w i t h d i x o n r i n g packing. In the m i d d l e of t h i s column, DT is w i t h drawn in a tank t o g e t t r i t i u m a c c o r d i n g t o e q u i l i b r i u m r e a c t i o n 2 DT
