Investigation of the SVRE influence on the safety of large size sodium fast reactor


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The article provides analysis of ULOF type BDBA for different designs of BN1200 reactor
core with MOX fuel. The design feature of the reactor core is the presence of sodium plenum
above the fuel area, significantly reducing SVRE, similarly to what was done earlier in the
BN800 reactor. SVRE calculations were carried out by two codes:
– TRIGEX – engineering code for fast reactors neutronics calculations in the diffusion
approximation and threedimensional GEXZ geometry;
– MMKKENO – precision code for reactor characteristics calculation by Monte Carlo method.
Multigroup data library ABBN93 and data preparation system CONSYST are used in the
two codes.
Studies have shown that sodium removal from the core only gives positive effect linearly
dependent on the density of sodium. The results of calculation obtained by the diffusion
and transport codes are in a good agreement. Sodium removal from the plenum gives a
negative effect, which is nonlinear over height. The results of its calculation by the transport
codes show higher (by ~0.2 %?k/k) positive value than that obtained by diffusion method.
To increase inherent reactor safety in ULOF type accidents, a modified core design with axial
layer of depleted uranium dioxide was also studied.
Computational studies on the worst conceivable scenario of ULOF type BDBA confirmed
the effectiveness of sodium plenum to ensure inherent safety of the large size reactor.
Introduction of depleted uranium axial layer into the core would further increase reactor
inherent safety.

1. Matveev V.I., Chebescov A.N., Cerny V.A et al. Studies, development and justification of core with zero sodium void reactivity effect of the BN800 reactor . International Topical Meeting, Obninsk, Russia, Oct. 37, 1994. Proceedings Volume 1, pp. 145; 159 (in Russian).
2. Poplavsky V.M., Matveev V.I., Eliseev V.A. Issledovanie vliyaniya pustotnogo effekta reaktivnosti na technikoekonomicheskie charakteristiki i bezopasnost perspektivnogo bystrogo reaktora. Atomnaya energiya. 2010, v. 108, no. 4, pp. 230235 (in Russian).
3. Poplavsky V. et al. Studies on Influence of Sodium Void Reactivity Effect on the Technical and Economic Characteristics and Safety of Advanced Fast Reactor. Journal of Nuclear science and Technology. 2011, v. 48, no 4, pp. 538546.
4. Volkov A.V., Kuznetsov I.A., Shvetsov Yu. E. Raschet kipeniya natriya pri avarii bystrogo reaktora s uchetom raspredelennosti parametrov po secheniyu TVS: Preprint FEI2787. Obninsk, 1999 (in Russian).

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