Re: PCM-1B Sole Release Procedure

[Keith Welch <welch@CEBAF.GOV>]

At the NPP where I worked, we placed automated frisking equipment as close
as possible to exits of contamination areas - effectively replacing the hand
frisk whenever feasible.  Main reason was the increased sensitivity and
consistency of getting a 'good' frisk at the point of exit.  Since we had
several large areas with local monitoring within the RCA, everyone who
worked in a C-zone got two frisks - one coming out of the zone, the other
leaving the RCA.  Some smaller or remote areas still used hand frisk.  But
we generally still had the second check on the PCM upon exiting the RCA.

Sounds like you've got the machine in the right place, but I also agree that
you may want to relocate your change area to a point outside and some
distance from the buffer area if at all possible.  Sounds like a high
traffic area which could cause headaches if/when you have contamination
incidents at the monitoring point.

My opinion only.  

K. Welch
welch@cebaf.gov
-------------------------------------------------------------


>>  From: Judd Sills <sillsj@GAT.COM>
>>
>>At 10:00 AM 11/8/96 -0600, you wrote:
>>>     To whom it may concern:
>>>     
>>>     I am a senior health physics technician at a D.O.E. facility in 
>>>     Washington State.  We are currently implementing a program using a 
>>>     Eberline Personnel contamination monitor (PCM-1b) as a sole and final 
>>>     release survey when exiting a contamination area.  I would like to ask 
>>>     you for some comments, but first let me give you some background on 
>>>     what we have here.
>>>     
>>>     We store highly radioactive waste in 177 underground storage tanks in 
>>>     areas known as farms.  These farms are fenced areas and have loose 
>>>     contamination on the ground and equipment up to 100,000 dpm/100cm2.  
>>>     Areas exceeding the 100K level are posted High contamination areas. 
>>>     We routinely perform entries into pits and install video cameras into 
>>>     these underground storage tanks.  Other work performed weekly are such 
>>>     things as pumping the radioactive liquids from the old leaking single 
>>>     shell tanks to the newer double shell tanks as well as other intrusive 
>>>     work.
>>>     
>>>     We have a "change"  trailer at the entrance to each farm.  This is the 
>>>     location that the worker dresses into Anti-contamination clothing
(pc's) 
>>>     and enters and exits the farm.  The change trailer contains a PCM-1b.  
>>>     About half the trailer is posted and controlled as a Radiological
Buffer 
>>>     Area (RBA).  The area posted as a RBA is considered to be a clean
area.  
>>>     The PCM-1b is located inside the RBA about 10 to 15 feet from the step 
>>>     off pad coming out of the Contamination Area.  Workers exiting the 
>>>     contamination area and those entering will be using the same change 
>>>     area.  There are no personnel assigned as a control point at any exit.
>>>     
>>>     Now my question:
>>>     
>>>     How would your facility handle personnel exiting the contamination 
>>>     area?  Would you require a hand and foot survey before stepping into 
>>>     the RBA?  Would you simply undress out of your Anti-C's and then 
>>>     continue through the RBA to the PCM-1b without any type of survey?  Do 
>>>     you do a full self survey before moving on to the PCM-1b?  Or how would 
>>>     you handle this?
>>>     
>>>     I would appreciate any help or comments you may have.  Please feel 
>>>     free to E-Mail me or call me at (509)373-2731.
>>>     
>>>     Thank You,
>>>     
>>>     Glenn Williams
>>>     Senior Health Physics Technician
>>>
>>I haven't seen anybody offer you any help on this, so I will give you my
>>opinions.
>>
>>First, answer a few questions:
>>(1)What has been your experience with surveys for contamination in the
>>RBA???  If
>>   the surveys show that you aren't having contamination migrating out
>>of
>>the undress
>>   area, then frisker survey (hands/feet, or full-body) may not be
>>warranted.  If it    is discovered frequently, then you need to be more
>>aggressive and
>>institute routine
>>   frisking prior to leaving the step-off pad.
>>(2)How frequent and how serious are your personnel contamination events?
>>If
>>they    don't occur very often and are generally low activity, then the
>>extra
>>   checks prior to crossing the RBA probably aren't warranted.  If the
>>events are
>>   frequent and/or serious, then extra precautions such as frisking are
>>warranted.
>>(3)You mentioned that the dress-out areas for entry and exit are common
>>for each
>>   tank farm.  By this, I presume that you mean that dress-out occurs in
>>these areas,
>>   and that workers store their street clothes there as well for
>>re-dress
>>after       exiting the contaminated area.  Assuming this to be the
>>case, I honestly
>>think
>>   that you need to have a MANDATORY policy that all workers MUST
>>successfully clear
>>   the PCM-1s prior to going ANYWHERE after exiting the Contaminated
>>Area.  You    should consider making the dress-out area outside of the
>>Restricted Area, so    that workers have to clear the PCMs to get to it
>>anyway.  The workers
>>should NOT be
>>   in this area until they have been checked for contamination under any
>>circumstances.
>>(4)You should review how good your workers are at both dress and undress
>>for use
>>   of protective clothing.  The dress-out and undress practices will be
>>directly
>>   related to the probability of contamination events.  If you can get
>>workers to
>>   wear the PCs properly, and be careful not to contaminate themselves
>>or others
>>   during undress, then you can probably have low frequency/minor
>>contaminations and
>>   a lighter degree of control in the RBA would be OK.  If workers are
>>not
>>good at
>>   contamination control, then you are probably going to have problems
>>controlling
>>   contamination no matter how much frisking that you do.  Go to the
>>start
>>of the
>>   problem and begin with work practices.  Drill the workers and make
>>sure
>>that they
>>   take it seriously.
>>(5)Make sure that your workers have a phone or intercom to get hold of
>>the
>>   Radiation Protection staff in the event of a contamination detected
>>at the
>>   PCMs.  Make certain that the work atmosphere is such that workers
>>know
>>that it
>>   is to their better interests to report contaminations to Rad
>>Protection.
>>If the
>>   workers are punished for transgressions, an un-manned control point
>>is asking
>>   for trouble.  If they don't feel threatened, and want to protect
>>themselves, this
>>   won't be risky.  If you leave the exits unmanned, you have to accept
>>that you
>>   are going to have some workers that won't call Rad Protection when
>>they
>>are con-
>>   taminated, and workers that will "blow by" the PCMs to prevent delay.
>>Motives
>>   for this type of behavior are astounding, but it does occur.  Having
>>Rad
>>Protection
>>   Technicians show up at the areas frequently to observe PCM practices
>>may
>>help.
>>   The PCM-1Bs are excellent monitors, but workers sometimes find the
>>sensitivity to
>>   be annoying, and quickly learn that they can lean away from the
>>detectors
>>and that
>>   the PCM won't "know the difference."  Some utilities have installed
>>video
>>cameras
>>   at the PCM stations to both monitor workers and to serve as an "ounce
>>of    prevention" in that workers will be less likely to skip monitoring
>>if
>>they think
>>   that it is likely that they would be caught.
>>
>>In summary, you need to have good training of workers, and a good
>>atmosphere for
>>the siutation that you describe to work well.  That is very possible,
>>but
>>you need
>>to head off problems by instilling the right attitude in workers, and
>>make
>>sure that
>>they know how to prevent problems, and share your desire to prevent
>>personnel
>>contaminations.
>>
>>These are my opinions, not my employers....
>>J. M. Sills, CHP             |   Office: (619)455-2049
>>General Atomics, Room 01-166C|      Fax: (619)455-3181
>>3550 General Atomics Court   |   E-Mail:  sillsj@gat.com
>>San Diego, CA  92121         |
>>
>Here is a shorter answer to how we handle this at West Valley, which is
another DOE facility.
>
>We have the individual hand frisk as close to the boundary of the
contamination area as possible if the 
>background allows.  We then have them go through a PCM-1b as they leave the
buffer area.  We have 
>found that the PCM-1b is very sensitive to beta contamination of the type
you will find at your tank farms.  
>Over the last few years the DOE has gone from wanting a hand frisker  as
the primary means of frisking to 
>wanting the PCM as the primary means.  This is my opinion.
>
>Dave Biela
>BielaD@wv.doe.gov
>