ML20070E647

From kanterella
Jump to navigation Jump to search
Forwards Control Sys Failure Review & Evaluation Program, Final Rept Re Outstanding Issues 14 & 15 of SER,NUREG-0835. Outstanding Issue 14 Addressed for Operating Reactors Per IE Bulletin 79-27
ML20070E647
Person / Time
Site: Clinton Constellation icon.png
Issue date: 12/09/1982
From: Wuller G
ILLINOIS POWER CO.
To: Schwencer A
Office of Nuclear Reactor Regulation
Shared Package
ML20070E650 List:
References
RTR-NUREG-0835, RTR-NUREG-835 IEB-79-27, U-0580, U-580, NUDOCS 8212170330
Download: ML20070E647 (2)


Text

I 4

'D

/LL/N0/S POWER COMPANY f3 (yg_99y_g 500 SOUTH 27TH STREET. DECATUR, ILLINOIS 62525 December 9, 1982 Mr. A. Schwencer, Chief Licensing Branch No. 2 Division of Licensing Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Washington, D.C. 20555

Dear Mr. Schwencer:

Clinton Power Station Unit 1 Docket No. 50-461 Outstanding Issucs No. 14 6 15 Attached is a copy of the report, prepared for Illinois Power (IP) by the Quadrex Corporation, regarding Outstanding Issues 14 & 15 of the Clinton Power Station Safety Evaluation Report (CPS-SER); MUREG-0853.

Outstanding Issue #14 is entitled " Capability for Safe Shutdown Following Loss of a Bus Supplying Power to Instru-ments and Controls". The staff requested that Illinois Power review the adequacy of emergency operating procedures to be used to obtain safe shutdown upon a loss of any Class lE or non-lE bus supplying power to safety- or non-safety related instruments and controls. This issue was addressed for operating reactors through IE Bulletin 79-27 (Nov. 1979). The results of this review indicate that the existing procedures are ade-quate to meet the safe shutdown requirements with the loss of bus power. No effects on the ability to achieve a cold shutdown condition were noted, thus no modifications to existing instu-ment and control systems are necessary. A Quadrex recommenda-tion to provide alarms and/or indications in the main control room to alert the operator to the loss of power to each bus is presently being evaluated by IP.

O\

1 np;s F ucc.kV 8212170330 021209 PDR ADOCK 05000461 E PDR

4 S.

U-0580 L30-82(12-09)-6 December 9, 1982 '

Page 2 Outstanding Issue #15 is entitled " Effects of Control Systems Failures". The Staff requested that IP identify any power sources, sensors, or sensor impulse lines which provide power or signals to two or more control systems and demonstrate that failure of these power sources, sensors, or impulse lines will not result in consequences outside the bounds of the FSAR Chapter 15 analyses or beyond the capability of operators or safety systems. In addition, IP was requested to review the designs to determine whether harsh environments associated with high-energy line breaks might cause control system malfunctions resulting in consequences more severe than those analyzed in the FSAR Chapter 15 or beyond the capability of operators or safety systems. This was addressed by IE Information Notice 79-22 issued September 1979. The results of this review indicate that the Chapter 15 events are bounding as described and that all safety criteria are met in spite of the postulated failures.

Therefore, no design modifications were found necessary as a result of this review.

In summary, IP believes that these results meet the intent of the investigations required by IE Bulletin 79-27 and IE Notice 79-22 and that no design modifications are required, at this time.

We would appreciate your review of these analyses at your earliest convenience so that these issues can be closed in the next supplement to the CPS-SER.

Sincerely,

G. E. Wuller l Supervisor-Licensing l Nuclear Station Engineering l

l TLR/lt 1

I cc: H. Abelson, NRC Clinton Project Manager H. H. Livermore, NRC Resident Inspector

! Rick Kendall, NRC Instrumentation and Control Systems Branch Illinois Dept. of Nuclear Safety 1

l l

i