Boiling water reactor radiation shielded Control Rod Drive Housing Supports

Conference · Wed Mar 01 04:00:00 EST 1995

OSTI ID:54688

Baversten, B; Linden, M J ^[1]

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1. ABB Combustion Engineering Nuclear Operations, Windsor, CT (United States)

The Control Rod Drive (CRD) mechanisms are located in the area below the reactor vessel in a Boiling Water Reactor (BWR). Specifically, these CRDs are located between the bottom of the reactor vessel and above an interlocking structure of steel bars and rods, herein identified as CRD Housing Supports. The CRD Housing Supports are designed to limit the travel of a Control Rod and Control Rod Drive in the event that the CRD vessel attachement went to fail, allowing the CRD to be ejected from the vessel. By limiting the travel of the ejected CRD, the supports prevent a nuclear overpower excursion that could occur as a result of the ejected CRD. The Housing Support structure must be disassembled in order to remove CRDs for replacement or maintenance. The disassembly task can require a significant amount of outage time and personnel radiation exposure dependent on the number and location of the CRDs to be changed out. This paper presents a way to minimize personal radiation exposure through the re-design of the Housing Support structure. The following paragraphs also delineate a method of avoiding the awkward, manual, handling of the structure under the reactor vessel during a CRD change out.

• Research Organization: Nuclear Regulatory Commission, Washington, DC (United States). Div. of Regulatory Applications; Brookhaven National Lab., Upton, NY (United States)
• OSTI ID: 54688
• Report Number(s): NUREG/CP--0143; BNL-NUREG--52440; CONF-940505--; ON: TI95008770
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
22 GENERAL STUDIES OF NUCLEAR REACTORS
ALARA
BWR TYPE REACTORS
CONTROL ROD DRIVES
ELECTROMAGNETIC RADIATION
OCCUPATIONAL EXPOSURE
REDUCTION
SHIELDING
SUPPORTS