located in the science valley of the yvette river some twenty miles south-west of the french capital , at the gateway to the parc de la valle de chevreuse , the town of gif-sur-yvette was home not only to the cnrs but also to the centre nationale de la recherche scientifique , the cea , commissariat l'nergie atomique , suplec , lcole suprieure d'lectricit , the lgep , laboratoire de gnie lectrique de paris , the centre nationale d'tudes and the national police academy .