Sewer Reconcentration & Solubility

[<cgj@nrc.gov> (Cynthia G. Jones )]

OK, OK.  I will try to respond to several of the
questions/concerns on this issue.  It is a difficult 
and complicated problem at best.

In 1991, NRC approved the changes to new Part 20 
permitting licensees to only release readily soluble, 
dispersible radioactive material (basically ground-up 
animal carcasses).  At the time the rule was finalized, 
NRC indicated (see 56 FR 23881) that a study was 
underway to help clarify the potential for human 
exposure due to radioactive material releases to 
sewers.  This study was published as NUREG/CR-5814.  
This study demonstrated that even in a worst-case 
scenario the new regs were sufficient to protect 
public health & safety.  A second study was undertaken 
in 1993 to look into the potential for reconcentration 
to occur and the result were published in NUREG/CR-6289.  
This study did confirm that reconcentration can 
occur (no surprize since sewer treatment facilities 
are designed to take out sediment, etc. and clean up 
the water!).

Also in 1991, Co-60 contamination was identified at 
the NE Ohio Regional Sewer District in Cleveland, Ohio. 
Following the 1991 incident in Ohio, the General 
Accounting Office (GAO) received a request from 
Senator Glenn (OH) to look into the sewer district's 
concerns.  GAO issued a report GAO/RCED-94-133, which 
was followed by a joint Glenn/Synar hearing on 
Capital Hill in June 1994.  At that hearing NRC 
Chairman Selin stated that no health & safety 
problem exists because studies to date have shown 
that in even the most conservative scenarios, doses 
to members of the public and sewer treatment workers 
are within 10 CFR 20 limits.  In responding to 
the GAO, NRC stated that we would work with EPA 
and the States to ensure a coordinated regulatory 
effort concerning this issue.

In addition to all this, NRC received a petition 
for rulemaking from NEORSD requesting (in part) 
that NRC consider revising Part 20 to require 
licensees to provide not less than 24 hours advance 
notice to the appropriate sewer treatment facility 
(this was noticed in the FR on Oct 20, 1993).  
As Les Slaback mentioned, NRC issued an ANPR 
on Feb 25, 1994 soliciting licensee and public 
comments on the reconcentration in sewer issue.  
Also, EPA has planned in the 1997-8 timeframe to 
conduct more studies on the potential for 
accumulation of radioactive material into sewers 
& we (NRC) will be working with them.

One of the difficulties encountered in this is 
that we have had several requests for information 
or direction, if you will, from sanitary sewer 
districts, interested States and members of the 
general public.  Our Office of General Council 
issued a letter to a facility in Laramie, WY on 
this very issue about 1-2 years ago.  Specifically, 
the sewer treatment plants may, (and in several 
cases such as St. Louis Metro Sewer District have) 
issue more stringent limits on radioactive releases 
to the sanitary sewer than NRC or Agreement State 
regulations.  For example, St. Louis sewer district 
limits the total discharge from all licensees to 
their sewer district to be no greater than 1 curie 
total from all 60 or so NRC licensees). In sharp 
contrast to our regs for releases of 1 curie or so, 
per licensee.

We have been working very hard on this issue for 
the past 3 years (gee-I really don't like to be 
called the "Sewer Queen" at the NRC! But it comes 
with the territory ! HA! HA!), and the staff is 
developing a paper for the Commissioners to review 
on this issue.  If you need more info, I suggest you 
check the documents listed above (they are all in 
Public Document Rooms), get a copy & read away.  
Any thoughts or suggestions you may have to this 
problem would be welcome & appreciated.  After all, 
several of us have been licensees too, you know!

Hope this helps....

Cynthia Jones.....CGJ@NRC.GOV
Division of Industrial and Medical 
  Nuclear Safety, NRC
******The opinions expressed above are my own 
and do not necessarily reflect the policy of 
the U.S. Nuclear Regulatory Commission.******