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Medina Modification Center

Also Known As: Medina Facility
State: Texas
Location: San Antonio
Time Period: 1958-1966
Facility Type: Department of Energy
 
Facility Description: The Medina Modification Center was established in 1958 for component testing, modification, repairs, and refinements. It operated until the early spring of 1966, at which point its functions were transferred to Burlington and Pantex.
 
Throughout the course of its operations, the potential for beryllium exposure existed at this site.
 
CONTRACTOR: Mason & Hanger-Silas Mason (1958-1966)
 
Listing:
Medina Modification Center is listed as a Department of Energy (DOE) site under the EEOICPA.
 
Special Exposure Cohort (SEC) Classes:
All employees of the Department of Energy, its predecessor agencies, and their contractors and subcontractors who worked at the Medina Modification Center in San Antonio, Texas, from January 1, 1958, through December 31, 1966, for a number of work days aggregating at least 250 work days, occurring either solely under this employment, or in combination with work days within the parameters established for one or more other classes of employees in the Special Exposure Cohort.
(Note: This class was established from Petition 203)
 
Compensation:
As of 08/30/2015, the total compensation paid under Parts B and E of the EEOICPA, including medical compensation, for workers suffering from the effects of having worked at the Medina Modification Center is $9,771,605.
 
Medina Modification Center Workers:
If you or your parent worked at this or any other DOE or AWE facility and became ill, you may be entitled to compensation of up to $400K plus medical benefits from the US Department of Labor. Call EEOICPA Counsel Hugh Stephens at 1-855-EEOICPA (336-4272) or fill out the form to the right, whether or not you have already filed a claim and even if your claim has been accepted or denied.
 
We can help with all OWCP (Federal Workers Compensation) claims, impairments, wage loss and health care. 2495 Main Street, Suite 442 Buffalo, NY 14214.
 
* SITE DESCRIPTION AND FUNCTIONS:
Medina Base, located on about 3,700 acres of Lackland Air Force Base southwest of San Antonio, was one of 13 WSAs created under the Armed Forces Special Weapons Project. Medina Base was constructed by the U.S. Air Force and the AEC between 1953 and 1955, with the first weapons components arriving in 1955. It was supported by SNL for the AEC and the Air Force. SNL, AEC, and the Air Force were all active at Medina from 1955 until early 1959, performing maintenance and quality assurance on nuclear components of weapons (Mitchell 2003).
 
The approved dates for applicability under EEOICPA for this site are 1958 through 1966 only.
 
During the AEC tenure, nuclear weapons and weapon components were stored by the AEC and maintained by SNL and Air Force personnel at the Medina WSA. WSAs were comprised of storage buildings that housed nuclear capsules, maintenance structures, waste burial sites, and bunkers used for storage of weapons casings. SNL personnel worked at Medina under contract to the AEC until early 1959 (Martin 2006a).
 
In 1958, MHSMC was chosen by the AEC to manage Medina Base, and construction of new facilities was undertaken. Three Gravel Gertie cells were constructed along with other specialized facilities that comprised the Medina Modification Center (Mitchell 2003). From April 1959 until 1966, MHSMC operated Medina for the AEC as a weapons modification and disassembly facility. The mission was to perform stockpile surveillance, modifications, retrofits, and weapon retirements (Carr ca. 1992). This work included inspections for corrosion and replacement of tritium reservoirs. Medina was operated by MHSMC until January 1966, when its mission was transferred to the Pantex Plant, and Medina Base was transferred back to the Air Force.
 
Site Description:
Lackland Air Force Base (AFB) is in the San Antonio metropolitan area in Bexar County, Texas (Figure A-1). Commercial and residential developments border Lackland AFB on the north, west, and south sides, and Kelly AFB borders it on the east. The western portion of Lackland AFB was the Medina Base, which is now designated the Lackland Training Annex. The Medina Base was comprised of four main areas designated as the 200 Area (general shops and stores), 300 Area (operations and storage), 400 Area (Plants 1 and 2, main production operations), and 500 Area (igloos and storage facilities). Two additional areas were the Burning Ground and the Railhead (Figure A-2) (Lamb Associates and Halliburton NUS 1995).
 
medina_mod_fig_a1_map
 
medina_mod_fig_a2_base_plan
 
November 13, 1963, Explosion:
On November 13, 1963, an explosion involving 50,500 kg (123,000 lb) of chemical high-explosive components of nuclear weapons occurred at the Medina site. Workers were placing subassemblies from dismantled atomic bombs into storage Igloo 572. The subassemblies, which were being stored for further processing and disposal, contained chemical high explosives, natural uranium, and DU. They were handled by a three-man crew – two forklift operators who moved them from a straddle carrier into the igloo and one man on the carrier.
 
Most of the load was in the igloo when, at about 10:24 a.m., the explosive in one of the subassemblies ignited. Seeing the flash, the drivers sprinted for cover, alerting the workers outside. For about 45 seconds the explosive burned, then it detonated with a force of more than 60 tons of TNT. The first explosion set off other subassemblies in the igloo and those still on the carrier. The igloo disappeared in a cloud of smoke and dust, leaving a crater some 20 ft deep. A large cloud of dust was seen near the ground moving downwind of the event.
 
In the 45 seconds between ignition and detonation, the three workers got away. Their injuries were minor. Adjacent igloos were not disturbed. The only known radioactive material involved was a mixture of DU and natural uranium. Fissile materials (enriched uranium or plutonium) were not involved in the accident.
*Source
 
DOCUMENTS:
 
NIOSH SEC Petition Evaluation Reports
Petition 203 (Jan 1, 1958 to Dec 31, 1966)
SEC Petition Evaluation Report, Petition SEC-00203, Rev #: 0
Report Submittal Date: May 31, 2012>/a>
 
Technical Basis Documents
Site Profile
Site Profile for Clarksville Modification Center with Supplementary Guidance for the
Medina Modification Center