U. S. experience with in-service monitoring of core barrel motion in PWRs using ex-core neutron detectors

Conference · Sun Jan 01 04:00:00 EST 1978

OSTI ID:6704859

Kryter, R C; Robinson, J C; Thie, J A

Coolant flow forces, pressure pulsations, and reactor primary system mechanical vibrations in a PWR combine to cause pendular (and other more complicated) motions of the reactor core support barrel within its surrounding pressure vessel. These motions are normally quite small (a few thousandths of an inch) and constitute no immediate safety problem, but in view of one past occurrence where some internal structural damage resulted, the U.S. Nuclear Regulatory Commission is considering making routine in-service monitoring for excessive core barrel motion mandatory for all PWRs. Should this be judged necessary, it is our opinion that quantitative in-service monitoring can be performed in a manner that is acceptable both to the Commission and to the nuclear plant operators by decomposing and interpreting the signals from the ex-core, power-range neutron monitors that are already a part of standard PWR instrumentation.

• Research Organization: Oak Ridge National Lab., TN (USA); Tennessee Univ., Knoxville (USA). Dept. of Nuclear Engineering
• DOE Contract Number: W-7405-ENG-26
• OSTI ID: 6704859
• Report Number(s): CONF-780589-1
• Country of Publication: United States
• Language: English

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IN-SERVICE INSPECTION
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MECHANICAL STRUCTURES
MOTION
PWR TYPE REACTORS
REACTOR COMPONENTS
REACTOR CORES
REACTORS
SUPPORTS
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