Axial power monitor rod issues and resolution for K-14.1

PDF Version Also Available for Download.

Description

A recent concern arose over the treatment of uncertainty associated with the K-Reactor axial power monitors (APMs). There are nine axial power monitor rods located at various positions in the K-Reactor core. By comparing the output of one sensor near the top of the rod to the output of another sensor near the bottom of the rod, the relative ratio of the neutron flux from the top to the bottom of the core can be determined. This ratio is called the roof-top-ratio (RTR) and is the output of a top sensor (Sensor 2) divided by the output of a bottom ... continued below

Physical Description

35 p.

Creation Information

Easterling, T.C.; Fields, C.C.; Hightower, N.T. III; Wooten, L.A.; Andre, S.K.; Apperson, C.E. et al. May 1, 1992.

Context

This report is part of the collection entitled: Office of Scientific & Technical Information Technical Reports and was provided by UNT Libraries Government Documents Department to Digital Library, a digital repository hosted by the UNT Libraries. More information about this report can be viewed below.

Who

People and organizations associated with either the creation of this report or its content.

Provided By

UNT Libraries Government Documents Department

Serving as both a federal and a state depository library, the UNT Libraries Government Documents Department maintains millions of items in a variety of formats. The department is a member of the FDLP Content Partnerships Program and an Affiliated Archive of the National Archives.

Contact Us

What

Descriptive information to help identify this report. Follow the links below to find similar items on the Digital Library.

Description

A recent concern arose over the treatment of uncertainty associated with the K-Reactor axial power monitors (APMs). There are nine axial power monitor rods located at various positions in the K-Reactor core. By comparing the output of one sensor near the top of the rod to the output of another sensor near the bottom of the rod, the relative ratio of the neutron flux from the top to the bottom of the core can be determined. This ratio is called the roof-top-ratio (RTR) and is the output of a top sensor (Sensor 2) divided by the output of a bottom sensor (Sensor 6). The RTR is important to the safety analyses because when the RTR is maintained within certain ranges, the severity of reactivity transients is limited. There are uncertainties associated with the equipment`s ability to measure the true roof top ratio. It was determined recently that sufficient uncertainty was not accounted for either in reactor operation or in the safety analyses. The concern about uncertainty was addressed for three separate issues. One issue dear with the linear response of the sensors for power ranges planned for K-Reactor operation. The second issue dear with overall uncertainty in the RTR channel. The third issue dear with apparent large ranges in confidence bands for the RTR at low reactor powers as represented by original vendor data. Plots of sparse vendor data indicated unacceptably large uncertainties in RTR would have to be accounted for at the power ranges planned for K-Reactor operation. These concerns were brought to management`s attention through the existing procedures for notification, irrespective of their potential impact on the restart schedule. Analyses have been completed to resolve the APM issues described above, and work is progressing to take the needed steps to change operational procedures.

Physical Description

35 p.

Notes

OSTI as DE92019634

Source

  • Other Information: PBD: May 1992

Language

Item Type

Identifier

Unique identifying numbers for this report in the Digital Library or other systems.

  • Other: DE92019634
  • Report No.: WSRC-RP--92-594
  • Grant Number: AC09-89SR18035
  • DOI: 10.2172/144911 | External Link
  • Office of Scientific & Technical Information Report Number: 144911
  • Archival Resource Key: ark:/67531/metadc627826

Collections

This report is part of the following collection of related materials.

Office of Scientific & Technical Information Technical Reports

What responsibilities do I have when using this report?

When

Dates and time periods associated with this report.

Creation Date

  • May 1, 1992

Added to The UNT Digital Library

  • June 16, 2015, 7:43 a.m.

Description Last Updated

  • Feb. 9, 2016, 4:49 p.m.

Usage Statistics

When was this report last used?

Yesterday: 0
Past 30 days: 0
Total Uses: 2

Interact With This Report

Here are some suggestions for what to do next.

Start Reading

PDF Version Also Available for Download.

Citations, Rights, Re-Use

Easterling, T.C.; Fields, C.C.; Hightower, N.T. III; Wooten, L.A.; Andre, S.K.; Apperson, C.E. et al. Axial power monitor rod issues and resolution for K-14.1, report, May 1, 1992; Aiken, South Carolina. (digital.library.unt.edu/ark:/67531/metadc627826/: accessed August 20, 2017), University of North Texas Libraries, Digital Library, digital.library.unt.edu; crediting UNT Libraries Government Documents Department.