Yes, equal to or greater than 100 ccpm on clothing, shoes, etc. is a Level 1 (or greater). I think that this definition is pretty much standard throughout the industry. If I'm wrong I'd like to know. But the question of whether this is reasonable definition of a PCE worth recording is open to debate. 100 ccpm on bottom of a shoe and 100 ccpm the skin or the face don't have the same risk significance. The whole question of how plants should be comparing their PCE experience should be revisited I think. Number of PCEs associated with positive whole body counts or skin dose >50 mrem might be a comparison worth making, for example.
Tom VanderMey, CHP Principal Radiological Engineer DTE Energy, Fermi 2 734-586-1539 [email protected] wrote: ----- To: <[email protected]> From: <[email protected]> Sent by: [email protected] Date: 10/17/2010 02:44PM Subject: RE: Powernet: PCE Question Mark, There are two issues here that should not be conflated: 1) What constitutes a Level 1 PCE and 2) What are the actual dose implications that result from the event. PER the EPRI guidance, detected contamination between 100 ncpm and 5,000 ncpm is a Level 1 personnel contamination event. In your example, 200 ncpm on the outside of a shirt and no detectable counts on the inside, this would be reported as a Level 1 Due to the tendency for discrete particles to migrate through materials, the idea behind surveying on the inside is to assess if this has occurred to any appreciable degree. Clearly, in your example the SDE would be zero and the DDE would be negligible; however, irrespective of the dose from a programmatic standpoint we need to look at cause, e.g., poor radworker practice, poor planning, etc. The essence of what I was saying is that verifying the inside reading allows for proper classification. For example, if you have a 200 ncpm on the outside of a shirt and a 600 ncpm reading on the inside, this would be at least a Level 2 and removal of the discrete particle from the material along with an unattenutaed reading would allow for the best possible assessment. Even in this secondary scenario while the dose is low to negligible, the causes / follow-up and corrective actions as a result of a personnel contamination event are what is relevant. Regards, Seth. From: [email protected] [mailto:[email protected]] On Behalf Of [email protected] Sent: Sunday, October 17, 2010 11:05 AM To: [email protected] Subject: RE: Powernet: PCE Question Thanks Seth. Good points. So if you found a 200 ncpm spot on the outside of a shirt that read no detectable on the inside, would it be reported a level 1? Created a "Level 0" for this type of find? thanks Mark Lewis Health Physics Division Manager San Onofre Nuclear Generating Station (D1N) Work: (949) 368-1140 [email protected] From: [email protected] To: [email protected] Date: 10/17/2010 09:24 AM Subject: RE: Powernet: PCE Question Sent by: [email protected] Yes, by doing this you can determine to what, if any extent the discrete particle has migrated through the material. This is important if a discrete particle is beneath the surface since most clothing materials will cause a certain level of beta attenuation. While Level 1 contaminations typically won’t result in the assignment of shallow dose, looking on both sides of the material is nonetheless a good health physics practice because of the ease at which material can mask the activity that is present. This will also allow for proper PCE classification. And, if the contamination results in having to calculated SDE dose you can use a more accurate MAF. Seth. ********************************************************************** Seth J. Kanter, CHP, RPT Sr. Health Physicist Palo Verde Nuclear Generating Station Mail Sta. 7397 5801 S. Wintersburg Rd. Tonopah, AZ 85354 Phone (623) 393-3130 Fax (623) 393-2487 Unless otherwise noted, all opinions are my own Liviu Librescu ********************************************************************** From: [email protected] [mailto:[email protected]] On Behalf Of [email protected] Sent: Sunday, October 17, 2010 8:48 AM To: [email protected] Subject: Powernet: PCE Question Friends, Do you look for >100 ncpm on the inside of clothing before classifying a clothing PCE as Level 1? Been recommended to me that EPRI guidance (excerpted below) is interpreted as suggesting that approach at some benchmark plants. The determination of the EPRI PCE level classification should be based on a frisker reading of the skin or the highest reading on clothing. For skin contaminations, a frisker reading should be the maximum reading with the frisker held approximately ½ inch away from the affected skin. For clothing, the frisker reading should be on the inside of the clothing with the detector faced away from the skin. EPRI “Guidelines for Industry Response to Personnel Contaminations Rev 1” thank you, Mark Lewis Health Physics Division Manager San Onofre Nuclear Generating Station (D1N) Work: (949) 368-1140 [email protected] Email Firewall made the following annotations --------------------------------------------------------------------- --- NOTICE --- This message is for the designated recipient only and may contain confidential, privileged or proprietary information. If you have received it in error, please notify the sender immediately and delete the original and any copy or printout. 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