ML20205A985

Forwards Safety Evaluation Re Util 840329 Response to Generic Ltr 82-33 Concerning Review of Isolation Devices That Interface W/Spds.Isolators Qualified & Acceptable for Interfacing SPDS W/Safety Sys

ML20205A985
Person / Time
Site:	Mcguire, McGuire
Issue date:	04/26/1985
From:	Rosa F Office of Nuclear Reactor Regulation
To:	Regan W Office of Nuclear Reactor Regulation
References
GL-82-33, NUDOCS 8505020185
Download: ML20205A985 (5)

Text

. ____-_______

t ,

j 60'JGY j; - APR 2 61985 5o - 3 Fo

! FEMORANDL'M FOR: W. Recan, Acting Brarch Chie f. Human Factori. Enqino.rinq branch Division of Human Factors Safety l

FROM: Faust Rosa, Chief, Instrumentation A Control Syster f.rarch Division of Systems Integration i

SUBJECT:

MCGUIRE lA2 . REVIEW OF ISOLATION DEVICES THAT IMERFACE WI!H

. THE SPD5

+

By letter dated March 29. 1084 Duke Power Company, the licensee for the McGuire 1&2 Nuclear Station, provided a response to Generic Letter 82 33.

In this response they provided a Safety Analysis Report (SAR) on their Safety Parameter Display System (SPDS). ICSB reviewed the SAR and cencluded it was incomplete and requested specific information on isolation devices. On October 29, 1984 further clarification was provided.

Enclosed is our Safety Evaluation Report (SER) which addresses the accrtt-ability of the isolators. Based on our review of the information provided, l

we conclude that with some exception the isolators are qualified isolatior l

devices and are acceptable for interfacing the SPDS with safety systems. The exception is discussed in the attached SER which also includes a request for l

additional infonnation. We conclude that implerentation of the SPDS m y continue pending review of this information, f 1

. . . . . r/:

...a Faust Rosa, Chief Instrumentation & Control 5)sters Branch Division of Systems integration

Enclosure:

Distribution:

As stated Docket file ICSB Rdg.

cc: R. Bernere J. Joyce (PF)(2)

R. W. Houston T. Dunning E. Adensam F. Rosa R. A. Birkel McGuire Subject File C. Miller J. Hane.cn (EG&G)(?)

G. Lapinsky

Contact:

J. Joyce. ICSB X29459 7,/ ~ ~~ ~ ~~~ ~~

OFC :IC5B/ :lC5B/DSI :ICSB/DSI

".~  :

TDunni

FPosa  :

NAME :J e:ct DATE :4/2 f/85 :4/ & 85 :4/ 1 0 /85  :  :  :

0FFICIAL RECORD COPY

. . _ . Mmso2 oar EA-

l i

l SAFETY EVALUATION - MCGUIRE NUCLEAR STATION SArtIT PARARtTER DI5 PLAT 5T5ILM (5PU5)

I. BACKGROUND in order to satisfy the NRC requirements concerning the SPDS Duke Power Company, the licensee for the McGuire 1 & 2 Nuclear Station, submitted a Safety AnalysisReport(SAR)onMarch 29, 1984. This report provided a description of the SP05 that is being implamented as part of the Operator Aid Computer System. The SAR did not address the requirements that the SPDS must be suitably isolated from safety systems to prevent the propagation of electrical 4

and electronic interference. On September 14, 1984, a request for additional information was sent to the licensee. Additional information on the isolators was submitted on October 29, 1984. Our evaluation addresses the qualification and documentation of the isolators as acceptable interface devices between the Class IE safety-related system and the SpDS. )

l

!!. DISCUSSION AN EVALUATION The Operator Aid Computer System provides a centralized computer based data and display system to assist control room personnel in evaluating the safety status of the plant. The top level graphical display contains a minimum set of plant parameters rep Msentative of the plant safety status and these con-

! stitute the Sp05. There are six Cri.tical Safety Function displays that are I

displayed continuously on 3 separate displays on the main control board for each unit. Each display has an associated decision tree on which the operator can call up specific trend information. Another display is available in the l i

technical support center.  !

~ - - . - - . _ _ _ _ _ . _ . _ . . . _ _ _ . _ _ _ - , . _ - . . _ _ - _ . . _ _ _ . . _ - .- _ .. _ _ _

'I, l

- i i

The SPDS at McGuire is software implemented on the operator aid computer (OAC) system. This system consists of a Honeywell model 4400 computer with bulk core memory. The system displays are driven by an Aydin 5205-C color graphic video display generator. Alarm typers, printers and floppy disk drives are also utilized. The OAC has both Class IE and non-Class 1E sensor inputs. The Class IE inputs are isolated frc' the OAC by qualified isolation amplifiers Westinghouse series 7300, that were reviewed and accepted by the staff in the following documents: (1) WCAP-8892-A " Westing-l house 7300 Series Process Control System Noise Tests," June 1977, (2) NRC j i letter, R. Tedesco to C. Eiche1dinger, Westinghouse Electric Company, l l

April 20, 1977.

The information supplied in Duke Power Company letter dated October 29, 1984 did not address the E-MAX isolators used on the radiation monitoring _ inputs to the SP05. The licensee shall provide the following informatior. to the NRC for confirmatory review of these devices.

Isolation Devices

a. For the E-MAX device used to accomplish electrical isolation, describe the specific testing performed to demonstrate that the device is acceptable for this application. This description should include elementary diagrams when necessary to ir,dicate the test configuration and how the maximum credible faults were applita to the device.

I

i l

0

b. Data to verify that the maximum credible faults applied during the test were the maximum voltage / current to which the device  ;

could be exposed, and define how the maximum voltage / current l was detemined. ,

l

c. Data to verify that the maximum credible fault was applied to j the output of the device in the transverse mode (between signal andreturn)andotherfaultswereconsidered(i.e.,openand shortcircuits).

! d. Define the pass / fail acceptance criteria for tnis device.

4

e. Provide a commitment that the isolation device comply with the environmental qualifications (10CFR 50.4g) and with the seismic qualifications which were the basis for plant licensing.

f. Provide a description of the measures taken to protect the safety systems from electrical interference (i.e., Electrostatic Coupling.

EMI, Common Mode and Crosstalk) that may be generated by the-SPDS.)

i 1

_ _ . _ _ _ ~ _ , - . . - . . . . _ . - , . . . - _ _ _ , _ . . . , _ . . , . _ . . . _ _ ~ . . ~ . . , - - , . ~ . . - , , . . . . , . - . . , _ - , - - , . - _ _ , ,

a III. CONCLUSION Based on our audit of the above documentation on Westinghouse series 7300 isolation amplifiers, the topical report, and the previous approval of this report, we conclude that the Westinghouse 7300 isolation amplifiers are acceptable for interfacing the OAC/SPDS with safety-related systems. We also conclude that this eqtsipment meets the Comission's requirements as stated in NUREG-0737, Supplement No. 1.

Adequate information was not provided by the licensee for the staff to con-firm acceptability of the E-MAX isolation devices that are used between the radiation monitors and the SPOS. The staff however concludes that it is acceptable for the licensee to continue implementing the SPDS progrem. but must provide adequate analysis and documentation on the E-MAX isolators for confirmatory review prior to SPDS operation.

l l

,. , - , - - - - - , - - -w-., - - - - - -,-- , - - - , , - - - -,.r. - , , , , -r, , - - , 7-,.. . e,,, ,m.. ,..,,