North Grafton, MA
Between 1958 and 1970, Wyman-Gordon was licensed by the AEC to receive handle magnesium thorium (3%) alloy materials and to manufacture Mg-Th forgings. During this time, approximately 167 cubic yards of solid magnesium - thorium (3%) waste and/or Mg-Th contaminated tools and small miscellaneous equipment were buried in approximately 25 trenches in the northeast sector of the plant site. Each trench is about three feet wide, six feet deep, and 25 feet in length. Waste was placed in each trench was nominally two feet deep and covered with four feet of soil. The bottom of the trenches were believed to be 4-5 feet about the ground water table. Total inventory of buried waste is approximately 42,000 pounds. On February 22, 1993, the NRC sent a draft Dose Assessment for comment to Wyman Gordon. The draft Dose Assessment indicated that the magnesium - thorium waste should be remedialed since doses from future use scenarios would be in excess of 1,000 mrem/yr for a unrestricted release criteria. On May 14, 1993, Wyman Gordon submitted response to the NRC disagreeing with many of the input parameters used in the draft Dose Assessment. Since 1990 to the present, Wyman-Gordon has had groundwater monitoring performed around disposal area and have been shown to be in compliance with the EPA drinking water requirements for gross alpha and beta. In October 2000, two additional monitoring wells were installed in the vicinity of the disposal trenches. These wells were installed as part of a Phase II - Comprehensive Site Assessment of the northeast portion of the site under the provisions of the Massachusetts Contingency Plan (MCP).
- Starmet Corp. (formerly Nuclear Metals) in Concord, Massachusetts
1. Site Identification
North Grafton, MA
License Status: License terminated
Project Manager: T.C. Johnson
2. Site and Operations
The Wyman-Gordon Company (WG) makes large titanium forgings for the aerospace industry. Between 1958
and 1971, WG had several Atomic Energy Commission licenses for the possession and use of magnesiumthorium
alloys and uranium. These materials were used in the manufacture of forgings for Department ol'
Defense classified projects. The last of these licenses was terminated in 1971. At the North Grafton site,
magnesium-thorium alloys containing between 2- and 3-percent thorium were disposed on site under 10 CFR
20.304. These disposals became a significant media issue on September 23, 1990, when an article appeared in the
Worcester Telegram describing the disposal and 1983 and 1984 ground water sampling issues.
In 1983 WG sampled on site monitoring wells in the immediate vicinity of the disposal area, which is located in
the northeast corner of the site. The results showed gross alpha, gross beta, and radium levels that exceeded
U.S. Environmental Protection Agency (EPA) drinking water requirements. Because of a large amount of
scatter in the data, additional sampling was performed byWG and by the Commonwealth of Massachusetts in
1983 and 1984. The resampling results showed radioactivity levels to be well within the EPA requirements. On
the basis of these results, both WG and the Commonwealth considered that there was no threat to public health
and safety. However, no formal analysis closing out this issue was documented by either WG or by the
Commonwealth. Further complicating the issue, an attorney for WG, without authorization from WG, transmitted
a letter to the Commonwealth requesting that the initial sampling data be held confidential until new
sampling could' be taken.
A consultant to WG had previously done a detailed hydrologic study of the WG site in support of submittals
made by WG to the EPA for compliance with Resource Conservation and Recovery Act (RCRA). This site
investigation included mapping the hydrogeologic system and the installation of monitoring wells, including in
the area immediately downstream from the magnesium-thorium disposal area. Three wells are located within
30 meters (100 feet) of the disposal area. V_,o of these wells are sampled annually by the consultant and analyzed
for hazardous chemical constituents. No radioactive assays have been performed since 1984. A third well is
located between two smaller disposal locations within the disposal area. Ground water sampling was performed
in October 1990 on samples from the three onsite wells adjacent to the disposal area and five offsite private
wells. The assay results indicate no ground water contamination in excess of EPA drinking water limits for gross
alpha and gross beta. Assays of sediment samples from the onsite wells indicate no thorium migration above
3. Radioactive Wastes
Approximately 22,600 kg (50,000 pounds) of the alloy material was disposed in an area in the northeast corner of
the site. The disposed material included scrap that hag no recycle value and contaminated equipment such as
grinders and other tools. The magnesium-thorium alloy wastes are buried and covered by 1.2 meter (4 feet) of
soil. The material is in an insoluble form. Radiation surveys taken immediately over the disposal trenches
indicate background levels of radiation.
4. Description of Radiological Hazard
There is no immediate threat to public health and safety. Ground water and ground water sediment sample
analyses indicate no migration of thorium and compliance with EPA drinking water requirements. The entire
area is fenced and access controlled.
5. Financial Assurance/Viable Responsible Organization
WG is one of the largest manufacturers of large titanium forgings for the aerospace industry and is financially
capable ofcleanup activities if remediation is required. Financial assurance requirements in the decommissioning
rule do not apply because the AEC licenses were terminated.
Status of Decommissioning Activities
The September 23, 1990, newspaper article prompted local State Senator John Houston to call a meeting of
Commonwealth and NRC regulators and Town Selectmen to discuss the roles and responsibilities of each
agency. This meeting was held on September 27, 1990. At this meeting, it was agreed that
• The Commonwealth and the NRC would participate in a split sampling program of ground water samples
taken on site and off site.
• The Massachusetts Department of Public Health would take offsite samples from several public wells located
in the vicinity of the disposal area.
• After the sample analyses were obtained and evaluated, the Town Selectmen would call a public meeting
and report the results.
NRC sample assays were performed by the Radiological and Environmental Sciences Laboratory (RESL) in
Idaho Falls, Idaho, and the assay data were transmitted to WG, State Senator Houston, Town of Grafton
Selectmen, and Massachusetts regulatory agencies on December 10, 1990. On January 29, 1991, NRC staff
participated in a public meeting in Grafton to discuss the results of the ground water sampling. Also in January
1991,the NRC requested WG to provide a dose assessment of the disposal area. In a letter dated March 11,
1991,WG informed the NRC staff that they would not perform a dose assessment, but would support the staff
by providing data that were available.
In February 1993,NRC completed a draft dose assessment of the WG site. This draft dose assessment indicates
that magnesium-thorium wastes should be remediated because predicted future doses are in excess of 10mSv
(1,000 mrem)/yr. A copy of the dose assessment has been sent to WG, local and State officials for comment by
letter dated February 23, 1993.At the request of Wyman-Gordon and the Grafton Selectmen the comment due
date was extended to May 14, 1993.
7. Other Involved Parties
The NRC staff has committed to keep the local and State government officials informed of all activities at the
8. NRC/Licensee Actions and Schedule
• interested parties submit comments on dose assessment May 1993