TY  - JOUR
N2  - In the case of large burnup, a control rod (CR) guide tube in the pressurized water reactor of a commercial nuclear power plant might bend. As a consequence, a CR drop experiment may indicate an event of a CR partially inserted and whether the CR should be deemed inoperable. Early prevention of such an event can be achieved by measuring two friction coefficients: the hydraulic coefficient and the sliding coefficient. The hydraulic coefficient hardly changes, so that the curvature of the guide tube can only be detected thanks to a variation of the sliding coefficient. A simple model for the CR drop is established and validated with CR drop experiments. If tmx denotes the instant of CR maximum velocity, a linear relationship between (tmx)_2 and the sliding coefficient is found.
PB  - American Nuclear Society
A1  - Blázquez, Juan
A1  - Vallejo, I.
A1  - García-Berrocal Sánchez, Agustin
A1  - Balbás Antón, Miguel
SN  - 0029-5450
Y1  - 2011/11//
AV  - restricted
JF  - Nuclear Technology
UR  - http://www.ans.org/store/j_13302
EP  - 289
SP  - 284
VL  - 176
IS  - 2
TI  - Control rod drop surveillance using two friction coefficients
ID  - upm15313
ER  -