Tham khảo tài liệu 'nuclear power operation safety and environment part 2', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | World Experience in Nuclear Steam Reheat 19 a b Fig. 9. Temperature variations at BNPP Unit 1 SHS channels at transitional regime Smolin et al. 1965 a - coolant inlet Tin and outlet temperatures Tout and b -sheath temperature. a Fig. 10. Variations of pressure drop a and sheath temperature b at BNPP Unit 2 during high-power start-up Smolin et al. 1965 . Start-up of Beloyarsk NPP reactors The start-up testing of the Unit 1 and Unit 2 reactors of the BNPP are described in this section. During the Unit 1 start-up both loops were filled with deaerated water water circulation was established air was removed and the pressure was raised up to 10 MPa and 3 MPa in the primary and secondary loops respectively Aleshchenkov et al. 1971 . Equipment was heated up at 10 - 14 of reactor power. Average heat-up rate was kept at 30 C h as measured at the separators. This value was chosen based on experience of drum 20 Nuclear Power - Operation Safety and Environment boilers operation though reactor equipment allowed significantly higher heat-up rate. No heat removal was provided during the heat-up to the 160 C coolant temperature at the reactor outlet. The water level was formed at 160 C in the bubbler and the excess heat started being released to the turbine condenser. When water temperature at the outlet of the SHS channels reached 230 C the heat-up was terminated. Total heat-up time was about 9 h. At the next step water was purged from SHS channels. The transient processes took place in the second loop while constant pressure and boiling-free cooling of BWs were provided in the primary loop. Reactor power was rapidly reduced to 2 of its nominal level and feedwater flow rate was reduced to provide water level in the SGs to purge SHS channels. Water-steam mixture from evaporators and steam from the steam loop were directed to the bubbler and then to the deaerator and the turbine condenser. The purging of SHS channels started after the level in the SGs had been formed. The .
