Patent Number: 
Section: claims

1. A measurement device for determining a boron concentration in a nuclear power station, comprising: an emitter to be disposed on a boron-carrying component with a coolable space with a cooling duct through which a coolant flows formed in between said emitter and said boron-carrying component; and  a receiver to be disposed on said boron-carrying component with a coolable space with a cooling duct through which said coolant flows, formed in between said receiver and said boron-carrying component;  spacers formed of a temperature-resistant and expansion-resistant material, said spacers maintaining a length of a measurement path between said emitter and said receiver substantially constant even in the event of a change in ambient conditions. 2. The measurement device according to  claim 1 , wherein said emitter and said receiver are held on said boron-carrying component by at least one fastener so as to require no structural measures or interventions on said boron-carrying component. claim 1 3. The measurement device according to  claim 1 , wherein said coolant is air. claim 1 4. The measurement device according to  claim 1 , wherein said coolant has a predetermined temperature. claim 1 5. The measurement device according to  claim 1 , which further comprises an additional insulation layer in said coolable space. claim 1 6. The measurement device according to  claim 1 , wherein each of said emitter and said receiver are disposed in a respective chamber. claim 1 7. The measurement device according to  claim 1 , wherein said emitter is a neutron source. claim 1 8. The measurement device according to  claim 1 , wherein said receiver is at least one counter tube. claim 1 9. The measurement device according to  claim 1 , which further comprises a shield respectively enclosing said emitter and said receiver. claim 1 10. The measurement device according to  claim 9 , wherein said shield includes a first layer of an absorbing moderator. claim 9 11. The measurement device according to  claim 10 , wherein said shield includes a second layer of neutron-absorbing material. claim 10 12. The measurement device according to  claim 11 , wherein said shield includes a third layer of austenitic material. claim 11 13. The measurement device according to  claim 9 , wherein said shield includes a layer of austenitic material. claim 9 14. The measurement device according to  claim 1 , which further comprises a casing housing said emitter and said receiver. claim 1 15. The measurement device according to  claim 14 , wherein said casing is formed in two parts. claim 14 16. The measurement device according to  claim 1 , which comprises at least one fastener for fastening said emitter and said receiver to the component. claim 1 17. The measurement device according to  claim 1 , which further comprises an evaluation device connected to said receiver. claim 1 18. The measurement device according to  claim 1 , wherein said emitter and said receiver are disposed substantially opposite one another on the component. claim 1 19. The measurement device according to  claim 1 , wherein said emitter and said receiver are disposed on the component such that a measurement signal received by said receiver is substantially a reflected measurement signal. claim 1