ML20058C678

Part 21 Rept Re Defect to Model 6717 Type B Package.Defect Involves Top Disk of Thermal Insulation Used in Model 6717 Shipping Barrel

ML20058C678
Person / Time
Site:	07106717
Issue date:	11/22/1993
From:	Roughan C AMERSHAM CORP.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20058C681	List: ML20058C678 ML20058C704
References
REF-PT21-93 NUDOCS 9312020531
Download: ML20058C678 (12)

Text

'NOV-22-1993 17r29 FROM AMERSKAM SENTINEL DIU TO 913014928187-P.02 AmenhamCorporation 40 North Avenue Burlington MA 01803 22 November 1993 M A U 2-2000

.tcl(800) 2251383 NRC Operations Center By facsimile 301-492-8187 FAmersham QSA Document Control Desk U. 5. Nuclear Regulatory Commission Washington, DC 20555 Referenco 10 CFR 21.21(c)(1)

Amersham Corporation is reporting a Part 21 defect in accordance with 10 CFR 21.21(c)(1) defect relating to the model 6717 Type B package. The defect involves the top disk of thermalInsulation used in the model 6717 shipping barrel, as shown in tho attached drawing.

The inside of the barrelis lined with a chalk liner which serves as thermal insulation to protect the contents of the barrel during the hypothetical accident j

fire condition for a Type B(U) package. This insulation includes the bottom, sides,and top of the barrel.

The defect that has been identified relates to the top portion of the liner which is -

supposed to be a single piece construction disk that fits inside the drum. We have discovered that this piece has recently been supplied as two sections glued at a lap joint. Upon this discovery on 16 November 1993, a nonconformance report was written on 17 November 1993 and evaluated by the Part 21 Review Board and determined to be a Part 21 defect on November 18 1993, i

This joint has been identified as weak and has broken during preparation for shipment, resulting in one large section and one small section. The small section is a circuler segment that includes approximately 15-20% of the diameter of the entire disk. This small section is easily damaged and will most likely be disposed of by a user. Amorsham has not shipped any barroic with a broken top disk,

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although it is possible the disk could become damaged during transport.

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NOU-22-1993 17:30 FROM AMERSHAM SENTINEL DIU TO 913014928187 P.03 i

i If the small piece is not present when prepared for transport, a direct thermal path to the package contents is created, and the insulation can no longer afford sufficient thermal protection for the model U-110, 20V, 40V and some early C-10

's and Gamma Centurys which have aluminum cases.

i With a section of the thermal insulation missing it is possible that a substantial safety hazard could be produced if the borrol contains an aluminum inner i

container and is then involved in a fire. This would allow the possibility of the aluminum case melting or deforming and potentially causing the lockbox of the inner container to become unsecured from the container. This could cause the source assembly to be shifted from the secured or stored position within the container, resulting in high radiation levels. While several different actions have to occur before this can happen, it is a possibility.

investigation has shown that we initially received this two piece construction from the supplier in November 1992, although this initial batch did not have a breakage problem. We received a second batch in August 1993 that exhibited the breakage problem described above. The thermal insulation protection is only nocessary for the aluminum containers, as the other containers authorized for use in the 6717 are manufactured of depleted uranium and steel cases and could withstand the firo test condition for a Type B package. The two piece construction of the top disk for these containers is not a safety issue, but a compliance issue with the Type B certificate. We are still requiring the same corrective actions for these as a user could potentially place a variety of inner containers (including aluminum caso containers) as authorized by the Type B certificate. A copy of this certificate is enclosed.

We are taking the following corrective actions to prevent any possible occurrence of this potential safety hazard.

1)

Amersham stopped shipment of any 6717 barrels containing a defertive top disk effective 18 November 1993.

2)

We are reviewing the shipping records to determine the users,that may have receivnd a defective disk. This will be complete by 26 November 1993.

3)

We are drafting a customer notice to be sent to all users of the barrels, advising them not to ship the barrel until a replacement top disk can be sent to them. A copy of this notice is enclosed and will be sent to customers boginning 29 November 1993.

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tOJ-22-1993 17:30 FROM Et1ERSHAM SENT1tEL DIU TO 913014928187 P.64 4)

We are working with the manufacturer of the disk to assure one piece construction and to obtain replacement disks as soon as possible.

Preliminary information from the supplier indicates that we may receive some replacement material by 24 November 1993.

Wn will update this notification as additional information is obtained. If clarification or additional information is needed, please contact me at (617) 272-2000 extension '210.

Sincerely, Cathleen Roughan Regulatory Affairs Manager i

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Copies:

Mr. Steven Baggett Sourco Containment Branch U. S. Nuclear Regulatory Commission Mr. William McDaniel 1

Facility Manager Amersham Corporation Mr. Charles Haughney, Chief Transportation Branch U. S. Nuctoar Regulatory Commission Regional Administrator U.S. Nuclear Regulatory Commission Region i

NOU-22-1S93 17:31 FROM ft1ERSHAM SENTINEL Dlu TO 913914928187 P.05 CUSTOMER NOTICE 22 November 1993

Dear Customer:

Amersham Corporation has recently become aware that the chalk liner used as the thermal insulation in the model 6717 shipping barrel may not meet the requiromonts of the Type B certificate. The top disk of this liner was designed to be a one piece construction, however we have received a shipment of disks that are of a two piece construction glued together at a lap joint.

It is possible that this type of construction could come apart, resulting in two separate pieces. One piece is much smaller than the other, approximately 15 % of the disk and could easily be lost. A drawing of this is enclosed for your information. For the 6717 barrel to meet all of the requirements of the Type B certificate, the top disk must De a one piece construction. The chalk liner (thermal insulation) is necessary for thermal protection of the inner container, and is a requirement for the package to meet the fire test condition for Type B packages. As some of the authorized inner containers in the 6717 are manufactured out of aluminum, (ie U-110, 20V, 40V and some early Centurys) this thermal protection is necessery to maintain security of the source assembly if the package were involved in a fire.

If part of this insulation is not present, there is a direct heat path directly to the inner container, which could cause sagging or deforming of an aluminum container. Whilo soveral different actions have to occur before there is a potential safety hazard we are taking corrective actions to prevent a possible occurrence.

Amersham has made a Part 21 notification to the NRC describing the potential safety hazard associated with this defect. We request that you do not ship the 6717 barrel until you have confirmed that the top disk is a one piece construction. We are working with the supplier of this disk to obtain replacement disks as soon as possible, and will replace them free of charge.

j Please inspect all 6717 barrels in your possession, and if you find that the top disk in a two piece construction please contact our Customer Service Department at 800-225-1383 for a replacement. If you have any further questions please contact the Regulatory Department at 800-225-1383 ext '210.

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NOV-22-1993 17:31 FROM AMERSKAM SENT!tEL DIU TO 913914928187 P.06 REV ENGINEER -

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