ML20212B898

Rev 0 to Preliminary Equipment Qualification Record for 3M Tapes

ML20212B898
Person / Time
Site:	Duane Arnold
Issue date:	12/19/1986
From:	Gucciardo T, Roly R IES UTILITIES INC., (FORMERLY IOWA ELECTRIC LIGHT
To:
Shared Package
ML20212B692	List: ML20212B820 ML20212B898 ML20212C114 NG-86-4544, Forwards Scotch Brand Tapes Maint Procedure GMP-ELEC-008, Installation Instructions, Rev 0 to QUAL-M345-00, Preliminary Equipment Qualification Record for 3 M Tapes & QUAL-A602-00, Qualification of Splices ..
References
QUAL-M345, QUAL-M345--R, QUAL-M345-00, QUAL-M345-00-R00, NUDOCS 8612290339
Download: ML20212B898 (10)

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NG-86-4544 3

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' PRELIMINARY ,-

.. EQUIPMENT QUALIFICATION RECORD

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- 3 M TAPES g<w -

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b Prepared by 'E / J2 j9,4 Approved by d _A f 9,ib.j$gg, 1

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' EVALUATION OF NG-86-4544 3M TAPE SPLICE INSULATION ,

1.0 INTRODUCTION

p;i, 2.0 REQUIREMENTS 2.1 PERFORMANCE SPECIFICATION 2.2 ELECTRICAL CHARACTERISTICS s

2.3 ENVIRONMENTAL CONDITIONS 3.0 QUALIFICATION PARAMETERS "P~

3.1 OPERATING TIME W4i% F' ~3.2 TEMPERATURE 3.3 PRESSURE 3.4 RELATIVE HUMIDITY 3.5 CHEMICAL SPRAY 3.6 RADIATION 3.7 AGING AND QUALIFIED LIFE 3.8 SYNERGISM 3.9 SUBMERGENCE 3.10 MARGINS 4.0 TAPE SPLICE PROCEDURE 5.0 TESTING ANOMALIES IN THE WYLE REPORT 6.0 MATERIAL COMPATIBILITY FOR USE ON DRYWELL PENtrRATION SPLICE 5 ,

6.1 MATERIALS CONSIDERED 6.2 MATERIAL COMPATIBILITY 7.0

8.0 REFERENCES

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1.0 INTRODUCTION

This report provides a preliminary evaluation of the environmental qualification of electrical cable splice insulation consisting of jScotch acket ,. 130C used as an electrical insulation with Scotch 33+ as a The Scotch 130C is a self vulcanizing product which is activated by stretching during installation. When installed in accordance with the manuf acturer's instructions the tape creates a void free solid dielectric insulation. The tape is rated through 69 KV and is designed to insulate splices whose self heating temperature can reach 130*C.

The specific configuration under consideration is insulated compression butt splices covered with an inner layer of 130C and an outer layer of 33+. The splices are contained in metallic raceway fittings or junction taxes.

The Wyle test report referenced by this evaluation is a preliminary report. Upon receipt of the final Wyle report, this evaluation can be finalized for inclusion in a qualification package. An evaluation of the final Wyle report will determine the need for additional analysis and/or calculations to support the qualification.

2.0 REQUIREMENTS Industry standards, such as IEEE Std 383 (1974), require that electrical cable splices be capable of functioning through postulated harsh environmental service conditions resulting from design bases events. Satisfactory performance of the cable should be evaluated by electrical and physical measurements appropriate to the type and application of cable splices during and following the environmental exposure. Functionality during the simulated environmental exposure is the primary indicator of successful performance. IEEE Std 383 (1974) requires cable to be energized at rated voltage and loaded with rated service current during simulated exposure; splices must function electrically throughout their exposure within specified electrical parameters.

2.1 PERFORMANCE SPECIFICATION-- - ~

At the DAEC, power, control, and instrtrnentation cables are located in environmentally harsh areas for EQ circuits and any splices on these cables would be located inside junction boxes. Generally, low insulation resistance and high leakage current is a potential concern for instrunentation cable. Debilitating effects on cable are greatly increased when exposed to demineralized water or chemical spray.

Although testing was performed with Nema 3 style boxes, this is not a requirement for qualification. The function required of the box is to protect the splice from direct spray. The boxes tested were equipped with drainage holes and were not watertight or sealed.

Therefore, any type of raceway fitting or box that protects the splice from direct spray will be acceptable.

For instrumentation cables the test report should demonstrate cable functionality during simulated environmental exposure per IEEE 384-81 Section 5. Leakage current during dielectric voltage withstand (DVW) testing shall be less than 10 mA. Insulation resistance will be greater than 1,000,000 ohms.

For power and control circuits, the test shall demonstrate cable functionality during simulated environmental exposure per IEEE 384-81 Section 7, leakage currents during DVW testing shall be less than 2 amps. Insulation resistance shall be greater than 100,000 ohms.

2.2 ENVIRONMENTAL CONDITIONS The 3M tape splice insulation must be qualified for the environmental conditions specified on the DAEC Environmental Service Conditions (QUAL-SC101). An evaluation of the qualification to these parameters is contained in Section 3.0 of this report.

3.0 QUALIFICATION PARAMETERS 3.1 OPERATING TIME These taped splice assemblies were subjected to a 5-day loss-of-coolant-accident (LOCA) simulated by Wyle Laboratories with test temperatures and pressures held higher than required throughout the duration of the test (Reference 1, Appendix IV). Addit.ional post LOCA operability is justified by testing at 265*F for 114 hours0.00132 days <br />0.0317 hours <br />1.884921e-4 weeks <br />4.3377e-5 months <br />.

Using the Arrhenius equation the equivalent operating time at 200*F can be calculated. ,,

/Z 1 11 )

t 1 = t2 exp(K ,

T- T2, /

1 where t1 = qualified life (hr) t2 = accelerated aging time (hr)

T1 = maximun normal temperature, 200*F or 366*K T2 = accelerated aging temperature, 265'F or 402*K Z = activation energy (eV)

K = Boltzman constant (8.617 x 10-5 eVf*K) t1 = 114 exp 1.15 1 1 8.617 x 10-) Y-402 ~;

= 2,985 hours0.0114 days <br />0.274 hours <br />0.00163 weeks <br />3.747925e-4 months <br />

= 124 days at 200*F This qualification envelopes the DAEC post-LOCA drywell temperature profile.

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3.2 TEMPERATURE The Wyle test maintained 355*F for 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> and 325'F for another 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> (Reference 1, Appendix IV). This provides a sufficient margin over the required DAEC LOCA transient. The remainder of the 5-day test profile was held at approximately 265'F and 22 psig. The combination of the higher peak temperature and higher temperature profile during the test induced environmental stress levels in excess of levels that would occur during the required postulated accident conditions. Because these cable splices successfully maintained

.their Class IE safety function during and after LOCA test, the temperature qualification is considered acceptable.

3.3 PRESSURE The peak pressure in the Wyle test was 55.3 psig (Reference 1, Appendix IV). Although this pressure is below the DAEC peak pressure per FSAR Sec. 3.11 pressure of 62 psig, this pressure is judged sufficient to establish qualification. The peak pressure of 62 psig is used for environmental qualification purposes and is conservative.

The most recent analysis of the DAEC post-LOCA containment response resulted in a peak pressure of 47.2 psig (FSAR Section 6.2.1.3.3.2).

When the tape is applied in accordance with Reference 5, there are minimal areas of entrapped air within the splice insulation.

Pressure increases will decrease these areas further improving the dielectric voltage withstand. Pressure induced moisture incursion will not progress into the taped area sufficiently to degrade the insulating value. There is no credible postulated failure mode caused by an increase in pressure, therefore, pressure qualification is acceptable for these splke assemblies.

3.4 RELATIVE FUMIDITY During the DBA tests on splice assemblies, steam was continuously injected into the test chamber (Reference 1, Appendix IV).

Therefore, relative humidity qualification is acceptable for these splice assemblies.

3.5 CHEMICAL SPRAY During the LOCA test the cable splice assemblies were sprayed with the required demineralized water spray (Reference 1, Appendix IV).

Because the specimens demonstrated satisfactory performance during the exposure, the splice assemblies are qualified for the demineralized water spray.

3.6 RADIATION The Wyle test successfully exposed the specimens to a total of 2.00 E08 rads (Reference 1, Appendix II). Therefore, these splices are qualified for 2.00 E08 raas.

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Beta radiation effects are negligible because the splices insi@ tha drywell are installed inside metallic junction boxes, raceway, or equipment items. During the-initial LOCA pressure transient, the beta emitting nuclides will not be substantially dispersed in the containment atmosphere; therefore, _ influx of air into the junction box will contain negligible beta emitting particles.

The thickness of the installed tape is approximately 150 mils which provides breakdown voltage to 12,000 V (at 80 V/ mil). Therefore, any Beta radiation will be attenuated within the outer layers of tape and the dielectric voltage withstand capability will be acceptable with substantial safety margin.

3.7 ELECTRICAL CHARACTERISTICS The tape splice insulation demonstrated acceptable electrical characteristics during and after LOCA testing (Reference 1). Refer to Table 1 for a simnary of the electrical characteristics of the tested splices.

3.8 AGING AND QUALIFIED LIFE Cable splice assemblies must be qualified for normal service at 150F or less.

Using the information from Reference 2, the qualified life can be calculated by using the Arrhenius equation.

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Z 1 Il 1 t1=t 2 exp (K T-T2 ,

1 where t1 = qualified life (hr) t2 = accelerated aging time (br)

T1 = maximum normal temperature,150*F or 338*K T2 = accelerated aging temperature, 265*F or 402*K Z = activation energy (eV)

K = Boltzman constant (8.617 x 10-5 eV/*K) ti = 482 exp 1.15 T1 1 (617x10-5

\8. i 338 -

402

= 265,110 hours0.00127 days <br />0.0306 hours <br />1.818783e-4 weeks <br />4.1855e-5 months <br /> = 29.6 year's Note: This activation energy was determined by Wyle Labs for the specific formulation of the 3M tape and will be included in the final report.

t 3.9 SYNERGISM The age-sensitive materials used in the 3M tapes listed in the test report sheet are ethylene propylene rubber (EPR) Scotch 130C and polyvinyl chloride (PVC)-Scotch 33+.

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In tha prts:nce of oxygen, synergistic effects are known to occur in EPR and PVC, even when the radiation dose rate is low. However, in an inert atmosphere of nitrogen, these effects are not known to exist (References 3 and 4).

The LOCA accident environment for these splices at Duane Arnold is in the drywell which is inerted with nitrogen during normal operation and during accident conditions. Therefore, the synergistic effects mentioned above are not applicable.

Other locations subject to High Energy Line Breaks are not inerted and will experience synergistic degradation. Test results of References degrad ation. 3 and 4 identify critical parameters which produce These parameters of temperatures greater than 175'F and simultaneous radiation dose rates of 4000 rads per hour. Areas experiencing these conditions require increased surveillance to monitor degradation. .

3.10 SUBMERGENCE All cable splices in the EQ Harsh areas are located above the maximum flood is notlevel elevations at the DAEC and qualification for submergence required.

3.11 MARGINS Sufficient margin has been applied during qualification testing to account for unquantified uncertainty such as the effects of production and installation variations and inaccuracies in test instruments. These margins are in addition to any conservatisms applied during the derivation of local environmental conditions for the equipment. Any specific exceptions to the above are evaluated for a given paraneter on a case-by-case basis.

4.0 TAPE INSULATION PROCEDURE The DAEC Repair Procedure (Reference 5) for " Scotch Brand Tape Insulation EQ Installation Instructions" uses splicing material and methods identical to those used for the Wyle test specimens (Reference 1) Q-1, Q-2, Q-3, and Q-4 which are:

a. Inner layers: 5 half-lapped layers of 130C

b. Outer layers: 2 half-lapped layers of 33+

5.0 TEST AN0MALIES IN THE WYLE REPORT In accordance with the cover letter for Reference 1, Wyle states that all of a the applicable Scotch tape samples (Q1, Q2, and Q4) are qualified to the intent of IEEE Standard 323-1974 tb anomalies concerning the Scotch 130C tape samples were identified in this report. A summary of results for these Scotch tape specimens is provided in Table 1.

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It is noted that the Scotch 33+ tape failed in all cases by splitting or shrinking exposing the Scotch 130C. The 33+ tape provides a external surface which assists in preventing physical contamination and abrasion of the 130C tape during construction. No dielectric voltage withstand properties are demonstrated or required during testing. Tapes other than Scotch 33+ providing a similar external protective surface would be acceptable to fulfill this function.

6.0 3M SCOTCH BRAND TAPE MATERIAL COMPATIBILITY FOR USE ON ORYWELL PENETRATION SPLICES This section documents the compatability of 3M Scotch 130C tape over compression splices to create a qualified splice insulation configuration inside containment at the DAEC.

6.1 MATERIALS CONSIDERED Scotch tape splices made in accordance with Reference 5 utilize 130C and 33+ tapes. Scotch 130C is a linerless, high-voltage, splicing tape with an ethylene propylene rubber (EPR) base. Scotch 33+ has a polyvinyl choloride (PVC) backing with a pressure-sensitive adhesive that is made with a butadiene rubber base. The PVC outer layer is not part of the splice insulation system. The 33+ is added as a jacket to provide physical protection to prevent abrasion and cover the stickiness of the 130C layer during construction.

The butt splices used at DAEC are insulated with unmodified nylon 6.6, (either Zytel-42, Celanese-1200 or equivalent), which is a thermoplastic polyamide or polyvinylidene flouride (PVF2 or KYNAR).

Wire insulation materials are a radiation or chemical crosslinked polyethlene per ICEA S-66-524 or ethylene propylene rubber. Cable jacket materials are neoprene or chlorosulfoned polyethlene (Hypalon) per ICE S-19-81. Wire materials are a tinned copper per ASTM 88 and ASTM B33.

6.2 MATERIAL COMPATIBILITY In the qualification test for Reference 1, Scotch 130C demonstrated no material incompatibilities with CSPE and PVC. 3M, Scotch 130C manufacturer has stated that there were no known material lincompatibilities between the Scotch tape materials and the materials considered in 6.1, even in high temperature and high radiation environments. Therefore, the qualification demonstrated in

' Reference 1 for the splice configuration in Reference 5 can be extended to Scotch tape when applied to any of the materials listed in 6.1 7.0 SUFNr.RY The Wyle test (Reference 1) docunented that the test specimens met the requirements of IEEE 323-1974 and 10CFR 50.49 and are qualified for use at the OAEC.

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8.0 REFERENCES

1.. Wyle Preliminary Test Report, Reference No.17859-P-12, dated November-7,1986.

2. Wyle Final Qualification Test Plan 17859-01, Rev. 8, Interim Procedure, Rev. 8-1.

, 3. NUREG/CR-2156, dated Jund 1981.

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4. NUREG/CR-2157, dated August 1981.

5. Repair Procedure-Scotch Brand Tape EQ Installation Instructions (RP-EQ-LATER).

6. Telecon between Bechtel and 3M, dated December 5,1986 (confirmation letter to replace this reference in final eval uation) .

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.e, .A & -,m' . - + .-E TABLE 1

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. POST-TESTED

SUMMARY

OF SCOTCH TAPE SPLICE SPECIMENS FROM THE WYLE TEST (REFERENCE 17859-P-12)

Minimum Insulation Maximum Leakage

. Intended Resistance ( )

Service Current (MA)

Test Acceptance Acceptance

Sample (Vac) Criteria Test Criteria Post-Test Comments Q1.130C/33+- 480 -2,200,000 > 100,000 3

-- <100 Although the outer tape l QMP 100-60 ~~

layer of the splice was <

cracked, the inner layer remained intact. The splice remained energized and met the plant-specific acceptance criteria.

Therefore, the splice is qualified for use at the DAEC.

Q2 130C/33+ 480 800,000 > 100,000 2

-- <100 Same as Q1. The white QMP 100-60 --

deposit (zinc oxides) found on the splice did not affect the operability of the

' splice. Therefore, the splice is qualified for use at the DAEC.

' Q3 130C/33+~

120 22,000,000 >1,000,000 0

- <10 Same as Q2. The light layer QMP-100-60 ~~

of rust on the wire did Inot affect the operability of the splice. Therefore, the splice is qualified for use at the DAEC.

Q4 130C/33+ 120 5,000,000,000 >1,000,000 2

-- <10 Same as Q1. The visible i

QMP 100-60 --

layer of blue glue did not affect the operability of the splice. Although the lead marked "1 Black" was cracked, the splice remained energized as shown by the

{

high insulation resistance

=

(IR) and low leakage current. Therefore, the splice is qualified for use i at the DAEC.

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