ML20052J068

Part 21 Rept Re Design Defect in Interrupt Structure of Eberline Instrument Corp Micro Computer Printed Circuit Boards,Initially Reported on 820112.Piggyback Boards to Be Supplied

ML20052J068
Person / Time
Site:	Clinton
Issue date:	05/12/1982
From:	Gerstner W ILLINOIS POWER CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
REF-PT21-82 U-0478, U-478, NUDOCS 8205240394
Download: ML20052J068 (4)

Text

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1606-L U-0478 L16-82(05-12)-L May 12, 1982 Mr. James C. Keppler Director, Region III Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, Illinois 60137

Dear Mr. Keppler:

10 CFR Part 21 Defect Eberline Micro Computer Printed Circuit Boards pocket No. 50-461/CPPR-137 On January 12, 1982, Mr. G.W. Bell of Illinois Powor dsO.

notified Mr. H.M. Wescott, U.S. NRC Region III, of a potential reportable defect per 10 CFR Part 21 regarding certain Micro Computer printed circuit boards supplied by Eberline Instrument Corporation. Based upon an evaluation, Illinois Power is notifying the Commission of a 10 CFR Part 21 defect. This report provides information as required by 10 CFR Part 21.21(6)(3).

(i) Mr. Roger Herd, President of Eberline, P.O. Box 2108, Santa Fe, NM 87501, notified U.S. NRC by letter to Director, Region IV, Office of Inspection and Enforcement, on December 21, 1981. Mr. G.W. Bell of Illinois Power informed Mr. H.M. Wescott, U.S. NRC Region III, by telephone on January 12, 1982 of a potential 10 CFR Part 21 defect.

Mr. W.C. Gerstner, Executive Vice President of Illinois Power, by means of this report hereby informs the Commission of a 10 CFR Part 21 defect.

(ii) Micro computer printed circuit boards (CPU III) used in the micro computer based radiation monitoring system.

The following equipment utilizes the above mentioned circuit boards:

Qty. Description Part #

(1) Control Room Control Terminal 11016-00 (1) Health Physics Office Control Terminal 11017-00 8205240394 820512 PDR ADOCK 05000461 S PDR MAY 17 ElR

_ _ _ _ _ _ _ _ _ _ _ . S N/9%

. J.C. Keppler May 12, 1982 NRC Page 2 Qtv. Description Part #

(2) Portable Terminal 11018-00 (14) Fixed Digital CAM 11006-00 (10) Portable Digital CAM 11007-00 (2) HVAC-PRM 11008-00 (2) SGTS-PRM 11009-00 (2) Post-Treatment PRMS 11011-00 (3) Analog Input DAM 11014-00 (iii) Eberline Instrument Corporation P.O. Box 2108 Santa Fe, NM 87501 (iv) The subject CPU III boards possess a design defect in the interrupt structure such that if two interrupts of increasing priority occur sequentially, with the proper amount of time between them, the interrupt data may be changing while it is being read by the micro processor.

This results in erroneous data with the effect that the computer resumes operation as if being powered up for the first time. Hence, total loss of old data and calibration parameters occurs. This defect was discovered during a testing program by the Eberline Instrument Corporation.

The safety hazard created by this defect is the possibility of an undetected release of radioactive effluents due to the fact that alarm setpoints may be exceeded without any abnormal indication from the radiation monitoring system. It would not easily be possible to determine the extent of the release, and the hazard created by such a release.

(v) Illinois Power was informed of the defect by letter from Baldwin Associates (IP Contractor and purchaser) on 1/81/82. Baldwin Associates was informed of the defect by letter from Eberline on December 23, 1981.

(vi) The following is a listing of the equipment containing the defective circuit boards, and the proposed locations of the same:

I

- J.C. Keppler May 12, 1982 NEC Page 3 Equipment Drawing Number Equipment Number (M01-) Location 1H13-P864 Control Room Control 800 Level MCR Terminal ORM0lJ Health Physics Ofc.

Control Terminal A23-1001-1 SA-S2-737 ORM04J Portable Terminal ORM05J Portable Terminal Fixed Digital CAMS (14) 1PR10S Turbine Bldg. CAM 1 1107-2 S-115-762 IPRllS Turbine Bldg. CAM 2 1106-2 N-104-737 lPR12S Turbine Bldg. CAM 3 1107-2 P-119-762 1PR13S Turbine Bldg. CAM 4 1106-3 S-129.7-737 IPR 14S Radwaste Bldg. CAM 1 1106-3 S-124.9-737 l IPR 15S Radwaste Bldg. CAM 2 1106-3 S-126.1-737 1PR16S Radwaste Bldg. CAM 3 1106-3 S-129.7-737 IPR 17S Radwaste Bldg. CAM 4 1106-3 S-128.7-737 1PR18S Auxiliary Bldg. CAM 1109-2 AF-124-778 1PR19S Fuel Bldg. CAM 1109-2 AF-124-778 1PR20S Control Bldg. CAM 1107-6 V-128-762 1PR21S Containment Bldg. CAMI 1108-5 B-5-803 IPR 22S Containment Bldg. CAM 2 1109-2 AH-121-778 1PR23S Containment Bldg. CAM 3 1108-5 C-4-803 IPR 24 S-33 S Portable Digital CAMS (10) l Portable CAM 1-10 OPR01S Common Station HVAC 1107-6 AE-125-762 Exhaust PRM OPR02S Common Station HVAC 1107-6 AE-125-762 Exhaust PRM OPR03S Standby Gas Treatment 1107-6 AE-124-762 Exhaust PRM OPR04S Standby Gas Treatment 1107-6 Al'-124-762 Exhaust PRM IPR 35 S Post Treatment Air 1105-3 E-126.1-702

, Ejector PRM IPR 41S Post Treatment Air 1105-3 E-126.1-702 Ejector PRM OUIX-PR050 Meteorological Data AC-130-781 OUIX-PR051 HVAC & SGTS Vents M10-1105-25 AE-124-762 OUIX-PR052 Liquid Radwaste F-126-737 (vii) A piggyback circuit board will be supplied by Eberline i

for each piece of equipment affected along with directions for installation, and an insert for the equipment description manual. This piggyback board

contains a latch which prevents interrupt data from changing while it is being read , and is designed to

, alleviate the problem with no change in the operating characteristics of the instrument.

I i

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e J.C. Keppler May 12, 1982 Page 4 NRC Eberline Instrument Corporatioc is responsible for supplying the piggyback boards (39 total: 37 necessary plus 2 spare) to Baldwin Associates at the Clinton Power Station. Illinois Power will direct the -

installation of the circuit boards. They will be installed prior to system acceptance tests.

(viii) In_Eberline's notification letter to the U.S. NRC, Region IV, Office of Inspection and Enforcement dated December 21, 1981, it was stated that the licensee or purchasers of Eberline Micro Computer based radiation monitoring systems were informed of the defect, where upon corrective action was outlined with each of them.

Our evaluation of this reportable defect is available for your review at our offices. I trust that this letter provides sufficient information for your review and analysis of the problem.

Sincerely, l l

'6?> dy %

W.C. Gerstner Executive Vice President cc: H.H. Livermore, USNRC Resident Inspector Director of 'nspection and Enforcement - 3 copies U.S. Nuclear Regulatory Commission Washington, DC 20555 Director-Quality Assurance Illinois Department of Nuclear Safety