ML20094N679
| ML20094N679 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 08/10/1984 |
| From: | Riedl T TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC) |
| To: | |
| Shared Package | |
| ML20094N669 | List: |
| References | |
| EQ-1ES(84)-164, NUDOCS 8408160340 | |
| Download: ML20094N679 (7) | |
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EQ/IES(84)-164 L
TEST REPORT l
Radiation Ana l ysis of the -Barton Mode l 288A Differential Pressure Indicating Switch for the Texas Utilities Generating Company.
Prepared by:
Approved by:
b-(() Nih h 62 >(
/
T.
J. Riedl C.
G.. Morris, Manager Class 1E Systems Class 1E Systems I
8408160340 840810 PDR ADOCK 05000445 1
A.
PDR a
D TABLE QE CONTENTS EECU QM TITLE P A GE 1.0 SCOPE 3
2.0
SUMMARY
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3.0 CONCLUSION
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1.0 SCOPE
-This report summarizes available information concerning the effects of gamma radiation on the material mechanical properties of the Barton Mode l 288A D/P Indicating Switch and jusii f les that f or a gamma dose of 1.61x106 rads there are no observable radiation effects which impact the materials' mechanical properties.
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SUMMARY
An evaluation was performed on the effects of gamma radiation on materia ! mechan ica l properties of the Barton Model 288A D/P Indicating Switch.
The organic materials of the Switch were Identified and evaluated for radiation Induced degradation of the mater ia l s' mechan ica l properties when expose j to a TID of 1.61x106 rads.
The higher level of radiation (> 104 rads) for this unit, which is located outside containment, is caused by the recirculation of reactor coolant through nearby piping following an accident.
The Inorganics and meta l l ics of the Switch were considered to be little affected by the radiation environment and are more radiation resistant than the organic materials.
A list of the organic materials and corresponding part numbers for the Barton 288A D/P Switch is shown in Table 1.
The radiation resistance characteristics of these materials is shown in Table 2.
AlI materia l s show a higher l eve l of radiation to l erance than the required 1.61 x 106 rad s.
Buna-N, f or wh ich damage begins at 7x105 reds, is used as a gasket for the bezel assembly and is considered not to effect the performance of the Switch.
Based on this inf ormation, degradation of the per f ormance of these materia l s wou Id not be expected as a result of an exposure to a total Integrated dose of 1.61 x 106 rads.
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a 3.0-CONCLUSION-In summary it can be conc l uded that the Barton Mode l 288A
~D/P Indicating Switch is quallfled to a
radiation environment of 1.61 x 10 6 rads for the Comanche Peak Steam Electric Station.
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TABLE I EM L DESCRIPTION MATERIAL-0228.0025B Hi ALARM PHENOLIC 0228.0024B LO ALARM PHENOLIC 0038.0033T TERMINAL BLOCK PHENOLIC 0226.0028C STOP, SNUBBER 30 SHORE NEOPRENE 0277.0026C BEZEL GASKET 60 SHORE BUNA-N 0001.0039R 0-RING FLANGE GASKET VITON INSULATION, WIRE VINYL (TEFZEL) i 6
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IABLE. Z Ebenotics Un f i l l ed pheno l ics exh ib it exce l l ent phys ica l and electrical tolerance to radiation.
Fillers have great influence, both positi ve and negati ve, on the composite materia l s.
Cellulose fillers are among the most sensitive materials.
Two studies concur that cellulose filled phenolics wilI suffer a 20-25%
decrease in e longation, tensile strength and impact strength at a dose of 5x106 rads.
Electrical measurements made in another study Indicate that electrical properties are not significantly changed to 2x107 rads.
Mineral filled pheno l ics show exce l l ent radiation stability, and are among the more radiation resistant plastics.
They are unaffected by a radiation exposure of 3.9x108 reds.
Mineral and f lock f i l led pheno l ics wi l I have radiation resistance between the l imits of ce l l u lose f i l led and minera l fiIled phenolics.
Enaa _H (Nitrile Rubber)
- Nitrile, as in the case of most rubbers, exhibits good to exce l lent radiation tolerance.
Damage begins at 7x105 rads.
The 50% demage level for tensile strength, elongation, set at break, compression set and shore hardness is reached between doses of 1x107 reds and 3x108 rads.
Vitoa Fluoropolymers are safely used to a dose of 1x106 rads for dynamic stress and 1x107 rads for static stress applications.
.V i n y t.
(TEFZEL)
Tefzel Insulation exhibits a decrease in elongation of approximately 25% at 2x107 rads and 50% at 3x107 rads.
ERQar_ Rag (Gasket)
Neoprene has been extensi ve l y examined in irradiation studies.
The resuits indicate that damage begins at around 2x106 rads.
The 50% damage leveI f or tensi l e strength, e longation, set at break, compression set and shore hardness is reached between doses of 1x107 rads and 1x108 rads.
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