ML18019B017
| ML18019B017 | |
| Person / Time | |
|---|---|
| Site: | Harris  |
| 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 0'*CIL:
50-400 Shearon Harris Nuclear Pouer Plant.
Unit 1> Carolina 05000400 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:
AOOED COPIEB RECEIVED: LTR I
ENCL Q SIZE:
TITLE:
QR Submittal:.Inadequate Core Cooling (Item IX. F. 2) ('L 82-28 NOTES: Application For permit renewal Filed.
05000400 RECIPIENT XD CODE/MANE PNR-A PD2 LA BUCNLEY, B INTERNAL: ADl'1/LFii1B NRR BAR PD1 NRR PMR-B DIR NRR/DHFT DIR NRR/DSRO/RSIB R(:N2 07 COPIES LTTR ENCL RECIP IENT ID CODE/NAi~fE PMR-A PD2 PD PMR-A RSB NRR BNR DIR NRR PWR-A DIR NRR SHEA> J 01 NRR/
ENRIT L
04 COP IES LTTR ENCL EXTERNAL: 24X NRC PDR 02 LPDR NSIC 03 Oh TOTAL NU)i)HER OF COPIES REGUXRED:
LTTR 21 ENCL
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SNK Carolina Power & LIght Company JUK l3 SERIAL: NLS-86-205 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 INADEQUATECORE 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 3HE/pgp (3956OSU) cc:
Mr. B. C. Buckley (NRC)
Mr. G. F. Maxwell (NRC-SHNPP)
Dr. 3. Nelson Grace (NRC-Rll)
Mr. Travis Payne (KUDZU)
Mr. Daniel F. Read (CHANGE/ELP)
Mr. T. S. Moore (ASLAB)
Mr. H. A. Wilber Wake County Public Library S.
~ Zimm rman a
er Nuclear Licensing Section Mr. Wells Eddleman Mr. 3ohn D. Runkle Dr. Richard D. Wilson Mr. G. O. Bright (ASLB)
Dr. 3. H. Carpenter (ASLB)
Dr. R. L. Gotchy (ASLAB)
Mr. 3. L. Kelley (ASLB) 411 Fayetteville Street e P. O. 8ox 1551
~ Raleigh, N. C. 27602