Control rod pattern exchange in a BWR/6 utilizing gang mode withdrawal

Conference · Wed Jan 01 00:00:00 EST 1986 · Trans. Am. Nucl. Soc.; (United States)

OSTI ID:6581889

Auvil, Jr, A B; Aldemir, T; Hajek, B K

The use of checkerboard pattern of alternating inserted and fully withdrawn control rods and the uneven void distribution in boiling water reactor (BWR) cores can cause large burnup gradients even after a short time of operation. To compensate for these effects, power has to be reshaped periodically (typically every two full-power months) by individually manipulating the control rods. During this manipulation process (called the control rod pattern exchange), the core power is reduced to 60% of nominal power by means of flow reduction to limit power swings to tolerable levels and to ensure that fuel thermal limits are not exceeded. A control rod pattern exchange by individual rod manipulation typically takes 4 to 8 h and represents a large cost burden to the utility in terms of reduced system output. The latest generation of BWRs, the BWR/6, possesses the capability to simultaneously move up to four symmetrically located control rods. The rods corresponding to a given gang may have rotational symmetry, mirror symmetry, or a combination of the two. This paper presents a pattern exchange procedure that exploits the capability of gang mode rod withdrawal to reduce the pattern exchange execution time and radial power distribution asymmetry associated with individual rod manipulation. The working model used in the study is the Perry Nuclear Power Plant Unit 1, located in Perry, Ohio, and owned by the Cleveland Electric Illuminating Company.

• Research Organization: American Electric Power Services Corp., Columbus, OH
• OSTI ID: 6581889
• Report Number(s): CONF-860610-; TRN: 87-021324
• Journal Information: Trans. Am. Nucl. Soc.; (United States), Vol. 52; Conference: American Nuclear Society annual meeting, Reno, NV, USA, 15 Jun 1986
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
PERRY-1 REACTOR
CONTROL ELEMENTS
POWER DENSITY
BURNUP
REACTOR CORES
REACTOR MONITORING SYSTEMS
VOID FRACTION
BWR TYPE REACTORS
ENRICHED URANIUM REACTORS
POWER REACTORS
REACTOR COMPONENTS
REACTORS
THERMAL REACTORS
WATER COOLED REACTORS
WATER MODERATED REACTORS
220400* - Nuclear Reactor Technology- Control Systems
210100 - Power Reactors
Nonbreeding
Light-Water Moderated
Boiling Water Cooled