Re: High Dose Rates IRM/SRM Replacement

[Bob Hite <BobHite@ies.iec-energy.com>]

The Duane Arnold Energy Center had an event in 1989 in which the cabling
from an IRM which was stuck in the core for an extended period of time was
removed and bagged without an adequate survey.  The high dose rates were
primarily from activation products in the cable insulation.  We have a lot
of information on this incident.  Please feel free to call me at
319-851-7628 for more information.

>>> MONICA S. HOELSCHER <LASMG@CCMAIL.CECO.COM> 11/13 11:51 AM >>>
     Subject: 
     Author:  PAUL G. KNOLL at LASALLE
     Date:    11/13/97 9:30 AM
     
     
     LaSalle Station has a concern with high dose rates encountered during 
     the replacement of the incore detectors, LPRM and SRM detectors 
     specifically.  Anticipated dose rates, based on history and detector 
     life, had led ALARA to establish an estimated "stop work" of 1.5 
     rem/hr.  Dose rates encountered were 20 rem/hr and 40 rem/hr on the 
     cabling.
     
     Question:
     
     1.  Have other stations encountered similar concerns where incore 
     instrumentation has been "hotter" than anticipated?  What were the 
     specifics?  Detector, detector incore life, dose rates seen and 
     location of dose rates, etc.
     
     2.  If so, was an evaluation performed to determine the apparent or 
     root cause of the problem?  What was the cause?  For example:  seal 
     failure or insufficient decay allowed.
     
     3.  Name of contact, title, company/station, e-mail and phone number.
     
     Reply to:  
     
     Paul Knoll
     Health Physics
     LaSalle Station
     815-357-6761, ext. 2885
     
     laspk@ccmail.ceco.com