ML20084A597

Supplemental Final Part 21 & Final Deficiency Rept U-80 Re Failure of Containment Cooling Fans to Remain in Safeguards Position Following Safety Injection Signal Reset.Initially Reported on 840403.Circuit Modified

ML20084A597
Person / Time
Site:	Callaway
Issue date:	04/20/1984
From:	Meyer B BECHTEL GROUP, INC.
To:	Deyoung R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE)
References
REF-PT21-84 IEB-80-06, IEB-80-6, U-80, NUDOCS 8404250121
Download: ML20084A597 (2)

Text

, .

1 i Bechtel Power Corporaton Engineers - Constructors

.5740 Shady Grove Road Gaithersburg, Maryland 20877 301 - 258-3000 April 20, 1984 Mr. Richrad DeYoung, Director Office of Inspection & Enforcement U.S. Nuclear Regulatory Commission Washington, D.C. 20555

Dear Mr. DeYoung:

File: 0490.4 SNUPPS Project, Bechtel Job No. 10466 Failure of the' Containment Cooling Fans

'To Remain in' Safeguards ~ Position

'Following SIS Reset at Callaway The purpose of this letter is. to provide supplemental information regarding the Final 10 CFR 50.55(e)/Part 21 Report U-80, filed by our client, Union Electric Company, on April 9,1984.

Following initial notification on April 3,1984, Union Electric sent its final report to the NRC Region III Office for a deficiency detected during preopera-tional testing of the Engineered Safety Features Actuation System at Callaway which involved the failure of the containment cooling fans to remain in slow speed (safeguards position) following the reset of a Safety. Injection Signal (SIS). This is contrary to NRC IE Bulletin 80-06, which requires the equip-ment to remain in its emergency mode upon removal and/or manual resetting of-the Emergency Safety Features actuating signal.

The deficiency is also reportable-under 10 CFR 21 in that in the process of making a site-unique Callaway design change to allow remote speed control'of the fans upon control room evacuation, the design change inadvertently modi-fied the control scheme function th c vaintains the fans-in slow speed follow-ing the reset of the SIS. The srfaty impact of the change on the operability of the' system has not been ev Ye; 20. Rather.than perform the extensive eval-uation which would be requirti u e .4siish. safety significance, the circuit was modified.

8404250121 840420

PDR ADOCK 05000483 , /m C .S' __

_ _ PDR;., ._

>f7

J_

j.."_

J Bechtel Power Corporation 4

Mr._ Richard DeYoung April 20,1984 Page 2' s

The circuit now contains an interlock that will block the fans from returning to high speed after the SIS is removed and/or reset. The fans will remain in slow speed until the operator acts to restore fans to normal (fast speed).

With the incorporation of this modification, the design of the containment

. cooling fan control circuitry is in compliance with NRC IE Bulletin 80-06.

Due to the nature of this design deficiency, we have concluded that it is unique to the SNUPPS Callaway Project, and does not apply to other Bechtel projects. We are, however, alerting our other divisions to this deficiency so that they can perform whatever investigation they feel are appropriate.

Sincerely yours,

7) ,f p

ig;7 Bernard L. eyers Project Manager JKJ/jmd cc: Mr. C. E. Rossi, Office of Inspection & Enforcement, USNRC, Washington, D.C.

Dr. T. E. Murley, Director, Region I, USNRC Mr. J. A. Keppler, Director, Region III, USNRC

~

Mr. J. Collins, Director, Region IV, USNRC Mr. N. A.-Petrick, SNUPPS Mr. S. J. Seiken, SNUPPS Mr._ R. Grant, Kansas Gas & Electric Company Mr. F. D. Field, Union Electric Company t

,8

x. .

%-