ML20084B366

Final Significant Const Deficiency Rept 94 Re Chemical Vol Control Sys Heat Trace Temp Drift.Temp Control Module Sensor Moved Opposite Circuit Board Face,Heat Sink Installed & Heat Trace Circuits Reworked

ML20084B366
Person / Time
Site:	Waterford
Issue date:	04/12/1984
From:	Gerrets T LOUISIANA POWER & LIGHT CO.
To:	Jay Collins NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
References
94, W3K84-0844, W3K84-844, NUDOCS 8404260198
Download: ML20084B366 (3)

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c, I OUISIANA P O W E R & L i G H T! P O Box soos. NEW onLEANS, LOUISIANA 70174 242 oeunoNoe sineer

. (504) 366-2345 g

UTIUTIES SYSTEM April 12, 1984 W3K84-0844 Q-3-A35.07.94 ggg Mr. John T. Collins Regional Administrator, Region IV U. S. Nuclear Regulatory Commission oll Ryan Plaza Drive, Suite 1000 gg l g g Arlington, Texas 76012

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REFERENCE:

LP&L Letter W3K84-0821 dated April 9, 1984

SUBJECT:

Waterford SES Unit No. 3 Docket No. 50-382 Significant Construction Deficiency No. 94

" Chemical Volume Control System (CVCS) Heat Trace Temperature Drift" Final Report In accordance with the requirement of 10CFR50.55(e), we are hereb> providing two copies of the Final Report of Significant Construction Deficiency No. 94,

" Chemical Volume Control System (CVCS) Heat Trace Temperature Drift".

If you have any questions, please advise.

I Very truly yours, l

T. F. Gerrets Corporate Quality Assurance Manager TFG:CNH:SSTG cc: Director Office of Inspection & Enforcement U. S. Nuclear Regulatory Commission Washington, D.C.

20555 (15 copies)

Director Office of Management-Information and Program Control

'U. S. Nuclear Regulatory Commission Washington, D.C.

20555 8404260198 840412 PDR ADOCK 05000382

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4 Mr. John T. Collins

. April 12, 1984 W3K84-0844 Page 2 cc: -Mr. E. L. Blake

~Shaw, Pittman, Potts & Trowbridge 1800 M Street, N.W.

Washington, D.C.

20036 Mr. W. M. Stevenson Monroe & Lemann 1424 Whitney Building New Orleans, Louisiana 70130 Records Center Institute of Nuclear Power Operations

'1100 Circle 75 Parkway, Suite 1500 Atlanta, Georgia 30339 Mr. W. A. Cross 7910 Woodmont Avenue Suite 1200-

.Bethesda, Maryland 20814 d

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FINAL REPORT OF SIGNIFICANT CONSTRUCTION DEFICIENCY NO. 94

-" CHEMICAL VOLUME CONTROL SYSTEM (CVCS) HEAT TRACE TEMPERATURE DRIFT" INTRODUCTION This report is submitted pursuant to 10CFR50.55(e).

It describes a deficiency in safety related heat tracing controllers. This problem is considered reportable under the requirements of 10CFR50.55(e). To the best of our knowledge,-this problem has not been identified to the Nuclear Regulatory Commission pursuant to 10CFR21.

t DESCRIPTION

.The safety related heat. tracing controllers were exhibiting the inability to remain within calibration over a period of time. This was due to the controller's sensitivity to changing ambient conditions. Secondly, approximately 66% of the."A" and "B" train heat trace circuits, for Boric Acid Make-up, required rework due to faulty construction or inadequate design.

SAFETY IMPLICATIONS If left:uncorrec'ted, these two conditions could result in deviations from the Technical Specification requirements to maintain minimum boration line temperatures.

' CORRECTIVE ACTION-

,The vendor (Raychem) provided a modification to prevent the safety related controllers from " drifting" out of calibration. This modification was necessary to thermally connect the terminal block to the sensor. This was accomplished by moving the. Temperature Control Module (TCM) sensor to the

-opposing circuit board face. The High Temperature Modules (HTMs) are already installed in this manner.

Installation of'a heat sink to the terminal block and insulation about the sensor was also required. The heat sink allows changes in ambient to be transmitted to the terminal block.which ensures the

-sensor reading terminal. block temperature..The' insulation will provide a stable environment for.the sensor and guard against sensing rapid ambient.

temperature changes. This work has been performed by LP&L under vendor.

supervision using vendor provided parts. The heat trace circuits which did L

not maintain the required design temperatures were reworked. The rework

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consisted of.providing.the correct' thermocouple orientation, rewrapping heater-cables'on piping and reworking of faulty insulation. FCR-E-3458 has been

issued to incorporate the modifications in the. vendor drawings. Also, an-acceptable operating pipe temperature range was established per the engineering requirements of DCN-E-967-R2.

J This report is. submitted as the Final Report.

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