ML17324B076
| ML17324B076 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 09/23/1986 |
| From: | Alexich M INDIANA MICHIGAN POWER CO. (FORMERLY INDIANA & MICHIG |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| AEP:NRC:0761E, AEP:NRC:761E, NUDOCS 8610070011 | |
| Download: ML17324B076 (6) | |
Text
XG"EBBION NBR FAC IL: 50-315 50-316 AUTH. NANE ALEXICH>N. P.
REC IP. NANE DENTONi H. R.
REGULATORY "'~ORNATION DISTRIBUTION SY".
8 (R 1DB>
86100700i i DOC. DATE: 86/OV/23 NOTARIZED:
NO DOC/(ET Donald C.
Cook Nuclear Potoer Plant>
Unit ii Ind iana 0
05000315 Donald C.
Cook Nuclear Power Planti Unit 2i Indiana 0
050003i6 AUTHOR AFFILIATION Indiana Zc Nichigan Electric Co.
RECIPIENT AFFILIATION OFFice of Nuclear Reactor Regulation.
Director (post 85ii25
SUBJECT:
Notifies of change in proposals in 830622 8c 840820 ltrs re plans to relocate two in-core thermocouples in upper reactor head region of plant. Thermocouples mill be left in present posxt1on at top of Fuel.
DISTRIBUTION CODE:
AOOID COPIES RECEIVED; LTR I ENCL 0 SIZE:~
TITLE:
OR Submittal:
General Distribution NOTES:
REClPIENT ID CODE/NANE PNR-A EB PNR-A FOB PNR-A PD4 PD Oi PNR-A PSB INTERNAL: ADN/LFNB N
CB G FILE 04 COP IEB LTTR ENCL RECIPIENT ID CODE/NAi~)E PWR-A EICSB PNR-A PD4 LA WIGQINQTONi D PWR-A RSB ELD/HDS3 NRR/ORAS RGN3 COPIES LTTR ENCL 2
EXTERNAL: EGM BRUSQUE> B NRC PDR 02 LPDR NBIC 03 05 TOT*L NURSER OP COPIES REQUIRED:
LTTR 24 ENCL
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INDIANA8 MICHIGAN ELECTRIC COMPANY P.O. BOX 1663I COLUMBUS, OHIO 432I6 September 23, 1986 AEP:NRC:0761E Donald C.
Cook Nuclear Plant Unit Nos.
1 and 2
Docket Nos.
50-315 and 50-316 License Nos.
DPR-58 and DPR-74 RELOCATION OF TWO INCORE THERMOCOUPLES Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D.C.
20555
Dear Mr. Denton:
The purpose of this letter is to notify you of a change in our plans to relocate two incore thermocouples in the upper reactor head region of the Donald C.
Cook Nuclear Plant.
In previous letters to the NRC (AEP:NRC:0761A, dated June 22,
- 1983, and AEP:NRC:0761C, dated August 20, 1984) we proposed to relocate two thermocouples, one from each channel, to monitor temperatures in the upper head region to assist in monitoring local vessel temperature conditions during natural circulation modes of operation.
We are now proposing to leave the thermocouples in their present position at the top of the fuel.
Since the above letters were written, this change has been determined to be costly and technically difficult to implement, and would not provide significantly enhanced information beyond the currently installed equipment.
Many hardware and procedural changes have been made to improve the operators'bility to detect inadequate core cooling (ICC) since the incore thermocouple relocation was first proposed.
We have newly upgraded incore thermocouples in Unit 1 and are scheduled to upgrade the Unit 2 thermocouples during the Unit 2, outage scheduled for 1987.
In addition, we have a subcooling margin monitor (SMM), Reactor Vessel Level Instrumentation System (RVLIS), reactor head vent valves, and new Emergency Operating Procedures (EOPs).
We therefore believe that sufficient instrumentation, used in conjunction with procedures, now exists to adequately assist the operators in detecting an ICC event during natural circulation.
The addition of fluid temperature monitoring instrumentation in the upper reactor head region will not significantly improve the operators'bility to detect an ICC event during natuxal circulation.
Furthermore, we believe the relocation of these two thermocouples is beyond the scope of the requirements of NUREG-0737 (Sections II.F.2; II.F.2, Attachment 1;
and Appendix B) and Regulatory Guide 1.97, Revision 3.
8610070011 860923 'i PDR ADOCK 05000315I
)
pnR Q
II Mr. Harold R. Denton AEP:NRC:0761E This document has been prepared following Corporate procedures which incorporate a reasonable set of controls to insure its accuracy and completeness prior to signature by the undersigned.
Very truly yours, P.
A xich 'L Vice President cm cc:
John E. Dolan U.
G. Smith, Jr.
- Bridgman R.
C. Callen G. Bruchmann G. Charnoff NRC Resident Inspector
- Bridgman
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