ML20153C964
| ML20153C964 | |
| Person / Time | |
|---|---|
| Issue date: | 09/16/1998 |
| From: | Steven Baggett, John Lubinski NRC |
| To: | |
| Shared Package | |
| ML20153C940 | List: |
| References | |
| SSD, NUDOCS 9809240257 | |
| Download: ML20153C964 (7) | |
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REGISTRY OF RADIOACTIVE SEALED SOURCES AND DEVICES SAFETY EVALUATION OF DEVICE i
No : NR-8104-D-8( ' -S DATE: SEP 161998 PAGE 1 OF 6 DEVICE TYPE : Pacemaker MODEL: Laurens-Alcatel 9000 l'
DISTRIBUTOR: Medtronics. Inc.
7000 Central Avenue NE CBC T275 Minneapolis,'MN 55432.
MANUFACTURER: Society Alcatel-Battery Paris, France SEALED SOURCE MODEL DESIGNATION: Not applicable - Part of Device
' ISOTOPE: Plutonium-238 MAXIMUM ACTIVITY: 2.9 curies (107.3 GBq)
. LEAK-TEST FREOUENCY: 6 months.(Explanted and Sources in Storage) s PRINCIPAL USE: (Q) Thermal. Generator
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REGISTRY OF RADIOACTIVE SEALED SOURCES AND DEVICES SAFETY EVALUATION OF DEVICE NO.: NE-8104-D-801-S DATE: SEP 161998 PAGE 2 OF 6 DEVICE TYPE: Pacemaker l
DESCRIPTION: l Medtronic, Inc. had made modifications to the source material (from plutonium-scandium alloy to plutonium oxide) and construction of the source capsule (from double to triple encapsulation) used in the Model 9000 pacemaker. Except for the source itself, no other change in the pacemaker of manufacturing process was introduced.
The heat source consists of nominally 0.160 grams (0.000353 Lb) plutonium-238 in the form of a ceramic pellet of plutonium 3
dioxide (PuO,y) of 88% cheoretical density 11.46 g/cm 1
(715. 43 Lb/ f t ) . At 90% plutonium-238 enrichment, this fuel has an associated maximum content of 0.6 ppm plutonium-236. As the plutonium dioxide fuel pellet is less dense than the previous fuel, the void volume in the inner capsule has been reduced 10 percent. The fuel is encapsulated in a 1.0 mm (0.0394") thick inner envelope of tantalum which in turn is encapsulated in a second envelope of platinum-20% iridium alloy which is 1.0 mm (0.0394") thick. Both capsules are sealed by tungsten-inert-gas (TIG) techniques, The fuel is triply encapsulated in an outer envelope consisting of 0.5 mm (0.0197") thick tantalum. The third encapsulation is sealed by electron beam welding.
Accounting for dimensional tolerances, a minimum gap of 0.12 mm (0.0047") is maintained between the second and third envelopes to provide for thermal expansion. The outer dimensions of the cylindrically shaped capsule (designated STO) are 9.5 mm (0.3743") diameter by 10.5 mm (0.4137") long.
The thermoelectric generator consists of the heat source and associated electronics which includes a thermopile of bismuth telluride semi-conductor elements and silicone base thermal insulation contained in a 0.5 mm (0.0197") thick titanium case of 2.4 cm (0.9449") diameter by 5 cm (1.9685") long. The thermoelectric generator weighs approximately 42 grams (0.0926 Lb)
- and has a power output of approximately 275 microwatts (o.369 HP)
(electrical).
l REGISTRY OF RADIOACTIVE SEALED SOURCES AND DEVICES SAFETY EVALUATION OF DEVICE NO.:. NR-8104-D-801-S DATE: $[P 16 )$$g PAGE 3 OF 6 DEVICE TYPE: Pacemaker DESCRIPTION: (Contd.)
The pulse generator contains the thermoelectric generator DC-DC converter circuitry and pulse generator demand circuitry which is encased in epoxy and packaged in a 0.5 mm (0.0197") thick titanium case of approximately 7.0 cm (2.7559") diameter by 2~6 cm (1.0472") wide. The case is hermetically sealed by electron beam welding. The pulse generator weighs approximately 172 grams (0.3792 Lb). The useful life of the generator (claimed by the manufacturer) remains 12 years, however, the design life (the potential life based on the fuel loading and radioactive ddcay) has been reduced from 40 years using the previous capsule 1 (STA)'to 32 years using the modified capsule (STO).
DIAGRAM: See Attachment 1.
LABELING: i The outer surface of each pacemaker is engraved with the following markings:
" Contact Health Authority For Disposal Medtronic Pulse Generator Laurens-Alcatel Model 9000 '
Pu-238 (radiation symbol), less than 3 Ci (date of sealing)
Caution: Radioactive Material U.S.A."
'In addition, each radioisotopic battery is labeled to show the Lyear of assembly, its-serial number, model number, the words
" Radioactive CIT-Alcatel", "Pu-238", the number 732, a source identification" number.and " Notify Civil Authorities if Found".
Each outer capsule envelope is marked with the date of sealing, L
.the serial number, the letter "F" and the radiation symbol.
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REGISTRY OF RADIOACTIVE SEALED SOURCES AND DEVICES SAFETY EVALUATION OF DEVICE NO.: NR-8104-D-801-S DATE: SEP 161998 PAGE 4 OF 6 DEVICE TYPE: Pacemaker PROTOTYPE TESTING:
The Model 9000 pacemaker has been designed and tested to withstand stresses associated with impact, crush and fire which could result from credible accidents involving a human body containing a pacemaker. Medtronic, Inc. has submitted information from results of direct tests and engineering analyses which has been evaluated by the staff and Atomic Energy Commission (AEC) consultants. This information shows that the fuel capsule and pacemaker has satisfied the testing requirements described by the AEC " Interim Safety Guide for the Design and Testing of Nuclear Powered Cardiac Pacemakers," dated March 26, 1974. All capsules (whether tested individually or as a component of a pacemaker) remained hermetically sealed as determined by, helium leak testing to a sensitivity level of at least 1 x 108 atm -cm /s. None of the tests resulted in a failure 3
of source integrity.
EXTERNAL RADIATION LEVELS:
Information concerning radiation profiles from previously described (May 23, 1973) pacemaker represent upper values since the addition of a third envelope (tantalum) will provide additional shielding. A radiation profile from the Model 9000 pacemaker with the STO type source was to be made available at a later date. Radiation levels at the surface of the pacemaker can initially produce maximum tissue dose rates of 3.2 mrem /hr (32 Sv/hr) from gamma radiation and 4.8 mrem /hr (48 uSv) from neutrons. Our opinion, based on advice from consultants is that these dose rates are not likely to produce measurable adverse effects in the patient. The amount of plutonium-236 (the ingrowth of daughters of plutonium-236 produces an increase in the gamma dose rate associated with the pacemaker) is determined by assay of the plutonium fuel and individual dose rate analysis of each unit to be 0.6 parts per million or less. Based on data submitted by Medtronic, Inc. It was estimated that the total dose rate the pacemaker will increase approximately 20 percent over a 10 year period.
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l REGISTRY OF RADIOACTIVE SEALED SOURCES AND DEVICES j SAFETY EVALUATION OF DEVICE NO.: NR-8104-D-801-S DATE: SEP 181999 PAGE 5 OF 6 DEVICE TYPE: Pacemaker OUALITY ASSURANCE AND CONTROL:
l Quality control procedures were reviewed and found acceptable as '
applied to design, materials control, fabrication, and product qualification testing. In this connection, pacemakers containing l the modified fuel capsule have been subjected to extensive ;
vibration and shock tests. Medtronic, Inc. has certified that '
each battery and fuel capsule will be the same as the prototype and the battery design. Materials used in the pacemaker construction, the fabrication process, components and documentation are all under Medtronic, Inc. control. Medtronic has certified that, among other things, each manufactured unit will be subjected to the following quality control procedures:
- 1. Five temperature cycles each at -5 to 70 C and with each cycle having a duration of 30 minutes.
- 2. Visual inspection, helium leak and swipe tests of the first and second encapsulations.
3, Inspection of the outer titanium housing by. helium leak test and x-ray radiography.
LIMITATIONS AND/OR OTHER CONSIDERATIONS OF USE
- The devices shall only be ditributed and serviced by specific licensees.of NRC or Agreement States.
- - Explanted'and devices in storage shall be leak tested at intervals-not to exceed 6 months using tecniques capable of testing 0.005 microcurie (185 Bq) of removable contamination.
- Handling, storage, use, transfer and disposal to be determined by the licensing authority.
- This registration certificate and information contained with in the references shall not be changed without the prior written consent of NRC.
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l REGISTRY OF RADIOACTIVE SEALED SOURCES AND DEVICES SAFETY EVALUATION OF DEVICE l t ,
I NO.: NR-8104-D-801-S DATE: ' O PAGE 6 OF 6 DEVICE TYPE: Pacemaker l SAFETY ANALYSIS
SUMMARY
1 Medtronics INC. ceased <the sale and the distribution of the Pacemaker Model 9000 in the 1970's. The distrbutor remains i committed and will continue to accept explanted devices for disposal. The distributor has indicated that currently Physicians do the service / follow-up on the pacers and distributor expects that Physicians would continue to provide this service as long as devices remain implanted.
l The device was orginally approved, by the AEC, for licensing l purposes based on an application dated August 7, 1969. There is not sufficient information on the file to perform a safety evaluation. Therefore, this registration certificate has been transferred to inactive status solely based on the original review and approval issued by the AEC and information contained in Medtronics letters dated November 01, 1997, and July 21, 1997.
REFERENCES:
The following support documents for the Model Laurens-Alcatel 9000 Pacer are hereby incorporated by reference and are made part of the registry.
Medtronic's letters dated November 01, 1997 and July 21, 1998.
ISSUING AGENCY:
US Nuclear Regulatory Commission j/.
/9 Date: Reviewer: / / b
dhn'W. Lubincki l
Date: SEP 161998 Reviewer: c b#
sIdven 6. Baggett
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REGISTRY OF RADIOACTIVE SEALED SOURCES AND DEVICES SAFETY EVALUATION OF DEVICE 1
HQ.i.1 NR-S104-D-801-S DATE" D I 6 laag ATTACHMENT 1 l
-CONNECTORS kS' #, M K>N FUEL CAPSULE p
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P.ULSE GENERATOR l RADI DEMAND CIRCUITRY ISOTOPIC POWER SUPPL' I
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