[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: 15 or 25 mrem per year?

Barry, in the context of releasing a plot of soil - if the risks are additive, wouldn't that cause a reduction in the DCGL for radioactive materials or residual concentrations of chemical toxics to meet the overall risk value of say: 1 E-6?



I have not seen this done except for radionuclides, but I had a fellow ask me during the final survey of a Rad site how I was going to keep the total risk below 1E-6 when considering both radiological and chemical toxics.



Dean Chaney

  ----- Original Message ----- 

  From: Barry E. Muller 

  To: HP Dean 

  Cc: William V Lipton ; jjcohen ; Redmond, Randy (RXQ) ; radsafe@list.vanderbilt.edu 

  Sent: Thursday, February 12, 2004 5:55 AM

  Subject: Re: 15 or 25 mrem per year?





  While working at a DOE superfund site ten years ago the remedial investigation/feasibility studies dealt with both rad and hazardous (chemical) constituents of concern.  In fact, while working on the "source term" calculation for the industrial CERCLA/RCRA Unit we considered both radiological and chemical contaminants to determine the proportion of materials that could be free released, those that were radiologically contaminated only, RCRA hazardous only, and mixed waste.  The calculations required the melding of two Oracle databases (engineering and environmental) and took about 12 hours to run on the VAXes of that era. 

  bem 

    

    



  HP Dean wrote: 



    Bill, 

    > Note:  Keep in mind that the NRC limit includes all pathways, while the 

    EPA 

    > limit is pathway specific. 



    Since the NRC limits only deal with radioactive materials, it begs the 

    question as to whether or not the EPA risk assessment ignore chemicals as 

    well when they are dealing with radioactive materials, or is some total site 

    risk calculated? 



    Since many site involve both toxic and radioactive materials, maybe someone 

    out there can comment on EPAs total site risk concept, if one exists. 



    Dean Chaney, CHP 



    ************************************************************************ 

    You are currently subscribed to the Radsafe mailing list. To 

    unsubscribe, send an e-mail to Majordomo@list.vanderbilt.edu  Put the 

    text "unsubscribe radsafe" (no quote marks) in the body of the e-mail, 

    with no subject line. You can view the Radsafe archives at 

    http://www.vanderbilt.edu/radsafe/