NLS9000196, Responds to Violations Noted in Insp Rept 50-298/90-09. Corrective Actions:To Ensure Future Clarity,District Will Revise Procedures to Clearly Indicate Acceptability of Okonite in Instrumentation Applications

Responds to Violations Noted in Insp Rept 50-298/90-09. Corrective Actions:To Ensure Future Clarity,District Will Revise Procedures to Clearly Indicate Acceptability of Okonite in Instrumentation Applications

ML20058M042
Person / Time
Site:	Cooper
Issue date:	07/31/1990
From:	Trevors G NEBRASKA PUBLIC POWER DISTRICT
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NLS9000196, NUDOCS 9008090306
Download: ML20058M042 (2)

Text

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GENERAL OFFICE n^

P.O. BOX 490. COLUMBUS. NEBRASKA 90002&99 Nebraska Public Power District "/A % 2 0i -,

NLS9000196 July 31, 1990 U.S.' Nuclear Regulatory Commission

-Attention: Docu.nent Control Desk Washington, D.C 20555 n

Centlemen:

Subject:

Response to NRC Inspection Report No. 90-09 Cooper Nuclear Station NRC Docket 50 298, DPR-46

Reference:

NRC Inspection Report 50-298/90-09 dated April 20, 1990.

~ NRC I'.spection Report 90 09 (Reference 1) documents the NRC irg ection of instrumentation calibration conducted at Cooper Nuclear Station (CNS) during the per'od April 2 6, 1990. Statements made ir the Inspection Report indicate an apr,arent misunderstanding may' exist regr.cding the use of Okonite splices in it.strumentation circuit applications. The Nebraska Public Power District-(District) hereby provides some additional information to clarify its position regarding use of Okonite T95/35 tapt splices in instrumentation applications.

The splicing of environmentally qualified equipment with Okonite T-95/25 tape is controlled through CNS Procedures 7.3.26.1, " Environmentally Qualified Okonite Tape Wrapped Cable Breakouts, Splices, and Terminations (Bolted)," and 7.3.26.2,

" Environmentally Qualified Okonite Tape Wrapped Splices and Terminations (Crimped)." During the inspection, the NRC inspector reviewed Revisions 3 and 2 of these procedures. ,NRC Inspection Report 90 09 states, in part:

"The inspector found that the (Okonite splicing] procedure [s] did not permit the use of taped splices -in harsh environments for instrumentation circuits."

The . environmental qualification of Okonite is documented in Equipment Qualification Data Package (EQDP) 224. Sections E.3, " Normal Functional Requirements," and E.4, " Accident Functional Requirements," of EQDP 224 each state:

" Splices provide electrical interfaces to Class 1E electrical equipment. The splices are used on power, control and instrumentation 1 cads."

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r 0'. ' U.S. Nuc1r r Regulct0ry C;mmicsien NLS-9000196 Page 2 of 2 6 EQDP 224, in Subsection 5 " Functional Testing," of Section F, " Equipment Evaluation," documents further the qualification of Okonite tape splices for use in instrumentation circuits. This section states that during qualification testin the Okonite splices demonstrated a minimum insulation resistance of 9 X 10{,, ohms. In addition, Design Input (DI) 2407, " Loop Accuracy Calculationt.,"

(Reference 20 of EQDP 224) demonstrates analytically the acceptability of Okonite ,

splices in instrumentation and control applications. Therefore, the environmental qualification of Okonite splicos~in instrumentation applications is well documented.

It is the intent of CNS Procedures 7.3.26.1 and 7.3.26.2 to allow use of Okonite tape splices in instrumentation applications. However, the District acknowledges '

that CNS Procedures 7.3.26.1 and 7.3.26.2 may need further clarification in their application statement. Section 1.0, " Purpose" of both of the above procedures  :

state: ,

"To provide Maintenance personnel with instructions for making Okonite tape wrapped splices and load terminations . . . on EQ (Environmentally Qualified) components and power or signal and control cables rated at 1000 volts or less . . ."

The above purpose statement allows use of Okonite splices in " signal" cables.

The intent of this statement was that " signal" carrying cables encompasses instrumentation circuits. To ensure future clarity, the District will revise 7' these procedures to clearly indicate acceptability of Okonite in instrumentation applications.

Please contact me if you have any questions.

Sincerely, G, revors

l. Senior Staff Advisor  ;

I' Nuclear Power Group t cc: U. S. Nuclear Regulatory Commission Regional Office, Region IV Resident Inspector Cooper Nuclear Station

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