ML18019B017

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Revises Info Provided in Util 840418 Ltr Re Inadequate Core Cooling Sys.Rcs Info Calculated by Erfis Computer.Info Does Not Impact Sser 1,Section 4.4.6
ML18019B017
Person / Time
Site: Harris Duke Energy icon.png
Issue date: 06/13/1986
From: Zimmerman S
CAROLINA POWER & LIGHT CO.
To: Harold Denton
Office of Nuclear Reactor Regulation
References
NLS-86-205, NUDOCS 8606170139
Download: ML18019B017 (4)


Text

'Ev LATORY INFORiNATION DISTRIBU ION 'SYSTE~)1 (RIDS)

ACCESSIOiN NBR: 8606170139 DQC. DATE: 86/06/13 NOTARIZED: NQ DOCKET 50-400 Shearon Harris Nuclear Pouer Plant. Unit 1> Carolina 050004000'*CIL:

AUTH. NAl"]E AUTHOR AFFILXATIQN ZINl1ERi~)AN> S. R. Carolina Poiiier 8c Light Co.

RECIP. NANE RECIPIENT AFFILIATION DENTON> H. R. Qf'Fice of'uclear Reactor Regulation> Direc tor (post 851125,

SUBJECT:

Revises info provided in util 840418 ltr re inadequate core cooling sos. RCS inFo calculated bg ERFIS computer. XnFo does not impact SSER 1> Section 4. 4. 6.

DIBTRIBVTION CODE:

TITLE:

AOOED COPIEB RECEIVED: LTR Submittal:.Inadequate Core Cooling (Item I ENCL IX. F.

Q2) SIZE:

('L 82-28 QR NOTES: Application For permit renewal Filed. 05000400 RECIPIENT COPIES RECIP I ENT COP IES XD CODE/MANE LTTR ENCL ID CODE/NAi~fE LTTR ENCL PNR-A PD2 LA PMR-A PD2 PD BUCNLEY, B PMR-A RSB INTERNAL: ADl'1/LFii1B NRR BNR DIR NRR BAR PD1 NRR PWR-A DIR NRR PMR-B DIR NRR SHEA> J 01 NRR/DHFT DIR NRR / I ENR T NRR/DSRO/RSIB L 04 R(:N2 07 EXTERNAL: 24X LPDR 03 NRC PDR 02 NSIC Oh TOTAL NU)i)HER OF COPIES REGUXRED: LTTR 21 ENCL

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SNK Carolina Power & LIght Company SERIAL: NLS-86-205 JUK l3 Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation United States Nuclear Regulatory Commission Washington, DC 20555 SHEARON HARRIS NUCLEAR POWER PLANT UNIT NO. I - DOCKET NO.50-000 INADEQUATE CORE COOLING INSTRUMENTATION

Dear Mr. Denton:

Carolina Power R Light Company (CPRL) hereby submits revised information concerning the Shearon Harris Nuclear Power Plant (SHNPP) inadequate core cooling instrumentation. This revises information provided via CPdcL letter dated April l8, l980, however, it does not impact Safety Evaluation Report (SER) Supplement l, Section 0.0.6.

The Reactor Coolant System (RCS) subcooling information at SHNPP is calculated by one of the two 100-percent redundant ERFIS computers (ERFIS Computer A or B). The ERFIS computers are integrated process and emergency response computers with a minimum availability of 99 percent. The ERFIS computer system calculates the saturation temperature corresponding to the RCS wide-range pressure. In conjunction with this, ERFIS Computers A and Bkoth screen all 5l core exit thermocouples (T/C) and calculate the core exit temperature based on the average of the five (5) hottest temperatures. This temperature (average of five (5) hottest), as recommended by the Westinghouse Owners Group, is compared with the calculated saturation temperature to derive the subcooling margin. Those calculations are updated at a minimum of once every 30 seconds. Additionally, all of the parameters are derived from safety grade instrumentation; i.e., qualified RVLIS displays for core exit temperature and RCS wide-range pressure indicators for pressure used in conjunction with steam tables. The margin to subcooling can be displayed on the SPDS and any of the Control Room and TSC7EOF CRTs. The margin to subcooling is also continuously recorded in the ERFIS archive for historical reviews.

If you have any questions on this subject or require additional information, please contact our staff.

Yours very truly, Sb06170139 860613 PDR ADOCK 05000400 t E PDR S. ~ Zimm rman a er Nuclear Licensing Section 3HE/pgp (3956OSU) cc: Mr. B. C. Buckley (NRC) Mr. Wells Eddleman Mr. G. F. Maxwell (NRC-SHNPP) Mr. 3ohn D. Runkle Dr. 3. Nelson Grace (NRC-Rll) Dr. Richard D. Wilson Mr. Travis Payne (KUDZU) Mr. G. O. Bright (ASLB)

Mr. Daniel F. Read (CHANGE/ELP) Dr. 3. H. Carpenter (ASLB)

Mr. T. S. Moore (ASLAB) Dr. R. L. Gotchy (ASLAB)

Mr. H. A. Wilber Mr. 3. L. Kelley (ASLB)

Wake County Public Library 411 Fayetteville Street e P. O. 8ox 1551 ~ Raleigh, N. C. 27602