Authors & Affiliations
A.I. Leypunsky Institute for Physics and Power Engineering, Obninsk, Russia
An ingress of natural uranium and thorium impurity in clad steel and heavy liquid metal coolant in gaseous fission products activity in cover gas and in delayed neutrons concentration in coolant estimated. The estimation made as an example calculation for reactor with fast neutron spectrum cooled by lead-bismuth eutectic. Cladding failure detection produce by measuring of gaseous fission product activity in cover gas and delayed neutrons abundance in coolant. With the leak tightness of all cladding kept intact the ingress of fission product included the delayed neutron mother nuclide into coolant is due to: process contamination of a cladding surface with fuel composition in the course of fuel element fabrication and natural uranium and thorium impurity in clad steel, fuel assembly cans and heavy liquid metal coolant itself. A fission product activity produced by that ingress in the primary circuit media is starting point to record a fuel element seal failure. Delayed neutron concentration in coolant produced by that ingress is the lower bound of significant clad failure that can be record.
cladding failure detection, heavy liquid metal coolant, natural uranium and thorium impurity, gaseous fission product, delayed neutrons
1. Polikarpov V.I., Filonov V.S., Chubakova O.V., Yuzvuk N.N. Kontrol' germetichnosti teplovydelyayushchikh elementov [Monitoring the tightness of fuel elements]. Moscow, Gosatomizdat Publ., 1962. Pp. 17, 32.
2. Sivintsev Yu.V. Radiatsionnaya bezopasnost' na yadernykh reaktorakh [Radiation safety at nuclear reactors]. Moscow, Atomizdat Publ., 1967. Pp. 263—264.
3. Slavygin P., Lusanova L., Miglo V. Regulation of the fission product activity in the primary coolant and assessment of defective fuel rod characteristics in steady-state WWER-type reactor operation. Proc. Techn. meeting. Bratislava, Slovakia, 2002.
4. Spravochnik khimika 21 veka [Chemist's Handbook of the 21st Century], (2018). Available at: www.chem21.info/info/687410 (accessed 10.04.2018).
5. Ryzhov S.B., Stepanov V.S., Klimov N.N., Bolvanchikov S.N. Reaktornaya ustanovka SVBR-100. Osnovnye proektnye polozheniya [Reactor installation SVBR-100. Basic design provisions]. Voprosy atomnoy nauki i tekhniki. Seriya: Obespechenie bezopasnosti AES - Problems of atomic science and technology. Series: Safety assurance of NPP, 2009, no. 24, pp. 7—12.
6. Voronkov A.V., Sychugova E.P., Dedul' A.V., Kal'chenko V.V., Nikolaev A.A., Rakshun E.V. Raschet kampanii reaktora SVBR-100 s uchetom dvizheniya organov regulirovaniya i kompensatsii [Calculation of the SVBR-100 reactor campaign, taking into account the movement of regulatory and compensation authorities]. Voprosy atomnoy nauki i tekhniki. Seriya: Obespechenie bezopasnosti AES - Problems of atomic science and technology. Series: Safety assurance of NPP, 2009, no. 24, pp. 38—43.
7. Manturov G.N., Nikolaev M.N., Tsibulya A.M. The system of group constants BNAB-93. Part 1. Nuclear constants for the calculation of neutron and photon radiation fields. Voprosy atomnoy nauki i tekhniki. Seriya: Yadernye konstanty - Problems of atomic science and technology. Series: Nuclear Constants, 1996, no. 1, pp. 59—98. (In Russian).
8. Bekman I.N. Yadernaya fizika. Kurs lektsiy [Nuclear physics. Lecture course]. Moscow, Moscow State University Publ., 2010. 511 p.