United States Nuclear Regulatory Commission - Protecting People and the Environment

Information Notice No. 83-32: Rupture of Americium-241 Source(s) Contained in a Well Logging Device

                                                           SSINS No.:  3835 
                                                           IN 83-32        

                               UNITED STATES 
                       NUCLEAR REGULATORY COMMISSION 
                    OFFICE OF INSPECTION AND ENFORCEMENT 
                           WASHINGTON, D.C. 20555 
                                     
                                May 26, 1983

Information Notice No. 83-32:   RUPTURE OF AMERICIUM-241 SOURCE(S) 
                                   CONTAINED IN A WELL LOGGING DEVICE 

Addressees: 

All NRC licensees holding a specific license to possess and use sealed 
sources containing byproduct or special nuclear material in well logging 
tools. 

Purpose: 

The intent of this information notice is to alert licensees to a potentially
generic problem identified in well logging tool recovery operations. Such a 
problem in Region I resulted in the rupture of an americium-241 sealed 
source(s). 

Description of Circumstances: 

On August 19, 1982, a well logging tool being used in coal exploration 
became stuck at the 420-foot level in a drill hole of 950 feet total depth. 
The tool included two sealed sources, each containing 250 millicuries of 
americium-241 as powdered oxide. The licensee began recovery operations 
including the use of drilling to enlarge the drill hole above the level of 
the stuck device. The licensee had successfully retrieved stuck tools on 
nine previous occasions using the same approach. The suspension cable used 
to lower the tool down the drill hole is designed to release at the point of 
attachment to the well logging tool when extra tension is exerted on the 
cable. In this case, when the tool initially became stuck the cable broke 
off about 80 feet above the device. On August 27, 1982, while drilling at a 
level which was thought to be well above the level of the stuck tool, one or 
both of the americium-241 sources was ruptured and contaminated the drilling 
mud used to cool and lubricate the bit. The most probable cause of the 
rupture was that the sources were drawn up to the drill by the remaining 
length of cable. The mud was discharged to a nearby retention basin and 
recirculated. The americium-241 contamination was not detected during 
licensee surveys because the survey instrument used was not sufficiently 
sensitive. Licensee representatives, believing the americium-241 sources 
still intact, replaced the first drilling rig with one more suited to 
planned recovery procedures and sent the first drilling rig to a second site 
nearby. 

On September 1, 1982, licensee representatives identified americium-241 
contamination in the retention basin and immediately notified the NRC. 
Radiological surveys and evaluations identified americium-241 contamination 
at both drilling sites, involving hand tools and approximately 6,500 square 
yards of ground. Contamination levels ranged from 100 to greater than 
1,000,000 disintegrations per minute per 100 square centimeters. Surveys at 
20 private 

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                                                              IN 83-32     
                                                              May 26, 1983 
                                                              Page 2 of 2  

residences, a motel, and the licensee's corporate offices identified 
contaminated shoes and clothing at the motel and contamination at nine 
private residences ranging from 20 to 600,000 disintegrations per minute per
100 square greater than 1,000,000 disintegrations per minute per 100 square 
centimeters. Surveys at 20 private residences, a motel, and the licensee's 
corporate offices identified contaminated shoes and clothing at the motel 
and at nine private residences ranging from 20 to 600,000 disintegrations 
per minute per 100 square centimeters. Seven of the homes in which 
contaminated articles were found belonged to work crew members; two homes 
belonged to local residents who had walked onto the drilling site before the
identification of the contamination incident. All contaminated articles were
bagged and returned to the original site for storage. No contamination on 
personnel was identified. The licensee is presently decontaminating the 
equipment and the site. 

Discussion: 

The above information identifies means whereby the integrity of a sealed 
source(s) can be jeopardized by well logging tool recovery procedures. This 
information notice is provided as an early notification of a possibly 
significant matter that is under review by the NRC staff. We suggest 
recipients review their procedures for well logging recovery to ensure that 
drilling or hole enlargement is not permitted during such operations until a 
clean break of the wireline is made at the point of attachment to the 
down-hole device. We also suggest recipients review their procedures to 
ensure that continuous monitoring of the surface (well head and/or mud 
discharge) will be made with a suitable survey instrument or logging tool 
(minus the source) in order to immediately alert the operators to possible 
source damage so that contamination can be properly controlled. 

If you have any questions regarding this matter, please contact the 
Administrator of the appropriate NRC Regional Office. 


                              James M. Taylor, Director 
                              Division of Quality Assurance, 
                                Safeguards, & Inspection Programs 
                              Office of Inspection & Enforcement 

Technical Contact:  J. Metzger 
                    492-4947 

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