Cold War Patriots Worker Stories


The Site Exposure Matrix

January 22, 2018

January 22, 2018

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The Site Exposure Matrix (SEM) is a tool developed by Department of Labor (DOL) to help claims examiners and claimants track Department of Energy (DOE) information on covered EEOICPA facilities.  The Alliance for Nuclear Worker Advocacy Groups (ANWAG) first proposed the tool in 2004. It was operational for DOL claims examiners around 2006 and DOL released a public version of the SEM after advocates pressured them to do so in 2010.

Basically the SEM is a database of information on toxins, illnesses, work processes, history, buildings, jobs, and a few incidents for most of the covered EEOICPA facilities.  Not all EEOICPA covered facilities have a SEM and at least one facility, the Dayton Project, has two.  It’s important to remember that while the SEM contains a lot of information it is NOT complete.  Much vital information has not yet been added. It’s a great place to start research but just because information is not in the SEM does not mean it does not exist.  The SEM is updated twice a year with leads to information being added or deleted.

The SEM contains separate sections for DOE facilities, uranium mines, mills, ore-buying stations and uranium transporters.  It defaults to the DOE facilities and you must click on one of the other sections for mines, mills, ore-buying or transport information.

A universal search on all toxins or illnesses for all DOE facilities can be done by selecting the blank at the top of the drop down menu (above the first name, Alba Craft).

I’ll use Mound Plant to demonstrate how to use the SEM.

  1. Go to the SEM website
  2. Click on the dot to the left of “Show DOE sites”
  3. Select “Mound Plant” from the drop-down menu and click on “Select”. The following screen will appear:

This webpage contains sections of Mound information.  Click on any underlined section for information on the topic.

  • Site history lists some, but not all, of the different names Mound was known by. It lists the contractors who operated Mound with the dates.  The date of the last information update is also listed.
  • Onsite location by alias provides a keyword search to identify Mound areas and buildings. For example, if you put “hill” into the search field and click the “Find matching onsite locations “ button, “Main Hill”, “SM/PP Hill”, and “Building 95” will be displayed.  For additional information clicking on the magnifying glass icon to the left of “Main Hill” will open the webpage for the Main Hill Area.
  • Area Information opens a page with a drop-down menu for 5 Mound areas. Each of the 5 choices contains a list of toxins, update history, some work processes, job categories, and the buildings from that area.  Again, clicking on the magnifying glass icon to the left reveals additional information.  At the top of the page are a number of secondary filters that can be chosen to limit the search.  But this is where you really need to remember that the data in the SEM is incomplete. For example, the use of the filters show no lung cancer caused by radon for chemists working in R-Building.  This is clearly nonsense since Mound has a Special Exposure Cohort (SEC) from 1959-1980 based on radon exposure in R-Building:
  • Building Information, Work Process Information, Labor Category Information work the same as Area Information
  • Work Process by Alias and Labor Category by Alias work the same as Onsite Location by Alias
  • Incident Information provides a drop-down menu which brings up 45 incidents that occurred at Mound. Selecting an incident opens a new page with a description of the incident, toxins, work processes, location, and job categories involved.  Again, the information provided is limited, as demonstrated in a 1955 Americium contamination incident that lists NO labor categories involved.



  • Incident Search by Text allows you to input keywords. For example, inputting “plutonium” into “Incident Text” reveals 7 records of plutonium contamination at Mound.


  • Incident Search by Related Item opens a table of incidents that occurred at Mound along with filters for toxins, locations, buildings, work processes, labor categories, as well as the name of the incident. Again, it is important to remember that not all incidents are included.

The SEM is a huge and complicated tool which will never be complete because new information is always being discovered.  It is a great starting point for claim research but can never be considered the last word.  While there is much room for improvement in SEM, both DOL and DOE deserve credit for their hard work in providing this information to claims examiners and claimants.