METHOD FOR OPERATING PRESSURIZED-TUBE URANIUM- GRAPHITE REACTOR AND CONTROL ELEMENT OF PRESSURIZED-TUBE URANIUM-GRAPHITE REACTOR Russian patent published in 2002 - IPC

FIELD: nuclear power engineering; control and protection systems of nuclear reactors. SUBSTANCE: method involves emergency introduction of negative reactivity by setting at least one control element to working travel into reactor core. In the process mean speed W of emergency negative-reactivity input at working travel should meet condition W = K•[ρ/(N)], where ρ is negative reactivity value β_eff; N is number of control elements set to working travel to reactor core; K is design-experimental factor chosen between 0.133 and 0.223, l/s. Control element has suspension that mounts sections with neutron-absorbing material fitted in its cooled channel. These sections are free to move along channel. Control element is also provided with sleeve preferably made of aluminum alloy. Sleeve has twelve section-accommodating individual channels equally spaced from its longitudinal axis. Each section is joined to suspension through shackles; section outer diameter d_s is chosen between 0.102 and 0.106 d mm, where d is sleeve outer diameter. Proposed design ensures that control element is entered in core throughout its entire depth and that amount of water in control and protection system is reduced within core. EFFECT: reduced load on drive, enhanced speed of control element introduction in core during emergency situations. 7 cl, 2 dwg