ML20248F979

Safety Evaluation Accepting Okonite Taped Cable Splice as Electrical Connection to Replace Terminal Blocks in Selected Low Voltage Transmitter Measuring Loops

ML20248F979
Person / Time
Site:	Hatch
Issue date:	09/20/1989
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML20247M396	List: ML20247M391 ML20248C223 ML20248F979
References
NUDOCS 8910100001
Download: ML20248F979 (4)

Text

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ENCLOSURE 1 SAFETY EVALUATION OF TAPED CABLE SPLICES AT PLANT E.I. HATCH UNITS 1 AND 2~

DOCKET NOS. 50-321 AND 50-366

1.0 INTRODUCTION

/ BACKGROUND The scope of this evaluation by SICB is limited to two of five unresolved items which are identified in the Equipment Qualification report on site inspections of Plant Hatch Units 1 and 2 from November 3 thru 7,.1986. The inspection report is identified as 50-321/86-35 (Unit 1) , and 50-366/86-35 (Unit 2). The two unresolved items, which question the qualification for service of OKonite taped cable splices, and States Company terminal blocks as used in Units 1 and 2, are identified as unresolved items 50-321/86-35-01 and 02 (Unit 1) and 50-366/86-35-03 and 04 (Unit 2) respectively. At that time, the inspection findings revealed that the licensee had fa'iled to demonstrate that plant performance requirements were satisfied for the use of OKonite cable splices an; the use v States.. Company terminal blocks _in Rosemount transmitter measuring loops during and following accident conditions.

In response to these inspection findings, Georgia Power Company contracted the Wylie Test Laboratories to conduct a series of qualification tests on the States Company terminal blocks to demonstrate their adequacy for use in various instrument measuring circuit applications. The terminal b*iocks were tested for service in RTD measuring circuits under accident and non-accident conditions. The results of these tests, documented in Wylie Test Report No.

I 48842, show that the potential worst case leakage current contributions from  !

the terminal blocks will not degrade operation of the RTD measuring systems when located either inside or outside primary containment areas. However, a l

8910100001 890920 PDR P

ADOCK 05000321 PDR l

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s transmitter loop error analysis of the potential worst case leakage current performed by the licensee, led to the replacement of terminal blocks in several selected transmitter circuits with a specially designed taped cable splice by OKonite. In order to qualify this replacement splice as a quality electrical connection in the applications specified, the licensee submitted to the NRC in August 1988, a summary evaluation report (SER) and an Environmental Qualification Report Evaluation (EQRE) to justify the use of the subject splice in selected low-voltage (50VDC) transmitter measuring circuits.

2.0 EVALUATION / CONCLUSION SICB has reviewed the licensee's SER and the EQRE regarding the adequacy of the OKonite taped cable splice qualification tests and has held related discussions with knowledgeable people from the Vendor Inspection Branch and the Plant Systems Branch. Based on these study efforts, SICB concludes that the OKonite taped cable splice is an acceptable electrical connection to replace terminal blocks in the selected low-voltage transmitter measuring loops. These selected measuring loops are identified in the Request for Technical Assistance (same subject) from Region II, (A. F. Gibson) to NRR (G.

C. Lainas) dated August 17, 1988. Details to support this SICB position follow.

l The licensee provided information in the submittal (i.e. SER and EQRE) to demonstrate that sufficient similarity exists between the Plant Hatch OKonite splice configuration and the tested splice configuration shown in OKonite Test Report NQRN-3. SICB's review of these configurations finds that the Plant Hatch splice configuration is consistant with the OKonite standard configuration for a typical 600 Volt AC circuit. The measuring circuits under review require a maximum transmitter voltage of 50 VDC to operate. To further support their position on this issue the licensee states * .

s "Since the transmitter circuit used at Plant Hatch is only operating at a maximum of 50 VDC, the insulation capacity of the splice relative to the circuit voltage is better than the tested 5000 Volt AC circuit splice.

Therefore, the leakage current of the Plant Hatch splice is less than the leakage current exhibited by the (5K VAC) test splice, which was already insignificant (i.e. 7x10-4 amperes) relative to (50 VDC) transmitter circuits."

In addition, the 5 KVAC splice was tested at a temperature of 340*F and a pressure of 115 psig for 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />, and then was subjected to reduced temperature and pressure conditions for an additional 130 days. In comparison, the Plant Hatch worst case operating conditions where the replacement splices are being used consist of a temperature of 218 F at a pressure of 1.93 psig for less tt?^

20 minutes. To preclude moisture intrusion, the splices are also located in NEMA 4 (watertight) enclosures. However, if the splices are to be submerged or immersed in water, they must be qualified by test (in accordance with the guidance of NUREG-0588) for the duration anticipated during design bases events.

In view of the above findings, SICB believes that sufficient evidence exists to conclude that: (1), moisture intrusion would not occur in the cable splices as used in the Plant Hatch applications; and (2), the potential leakage currents from the taped cable splice configurations used for the selected transmitter circuits specified are negligible. These conclusions are based on the assumption that the licensee has indeed evaluated the various installations of the taped cable splice relative to the worst case operating conditions (i.e.

abnormal high temperature, pressure, humidity, submergence, etc.) and has considered the time period in which the splice is qualified to operate. In summary, SICB concludes that the use of the OKonite cable splices at Plant Hatch is acceptable.

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ENCLOSURE 2

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SYSTEMATIC ASSESSMENT OF LICENSEE PERFORMANCE FACILITY NAME E.I. Hatch Units 1 and 2

SUMMARY

OF REVIEW / INSPECTION ACTIVITIES The SICB has completed its evaluation into the quality of OKonite taped cable splices being employed to replace terminal blocks in selected low-voltage transmitter circuits at Plant Hatch Units 1 and 2. The staff finds the -

licensee's actions taken surrounding this replacement effort to be acceptable.

NARRATIVE DISCUSSION OF LICENSEE PERFORMANCE - FUNCTIONAL AREA The information provided by the licensee effectively assisted the staff to conclude that the replacement cable splice is an acceptable electrical connection for use in the circuit applications specified. This submittal shows that the licensee was well aware of the significance of the issue by demonstrating that the subject cable splice's were indeec qualified to be used for the service intended. All staff concerns are resolved Author: V. Thomas DATE: 8/18/89 i

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