ML19331E433
| ML19331E433 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 09/08/1980 |
| From: | Crouse R TOLEDO EDISON CO. |
| To: | Reid R Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML19331E434 | List: |
| References | |
| RTR-NUREG-0578, RTR-NUREG-578 648, NUDOCS 8009100172 | |
| Download: ML19331E433 (1) | |
Text
C b
Docket No. 50-346 IS M License No. NPF-3 Acramo P Cact.ss Serial No. 648 C[,7"*"
e4191259-5229 Septeeber 8, 1980 Director of Nuclear Reactor Regulation Attention:
Mr. Robert W. Reid, Chief Operating Reactors Branch No. 4 Division of Operating Reactors United States Nuclear Regulatory Commission Washington, D. C.
20555
Dear Mr. Reid:
In Toledo Edison's letters of October 23, and November 21, 1979 (Serial Nos.
546 and 559) we committed to investigate the design of new instrumentation that could be used to provide unambiguous indication of inadequate core cool-ing conditions in the reactor coolant system of the Davis-Besse Nuclear Power Station, Unit No. 1 (DB-1). This related to recommendation 2.1.3.b of NUREG 0578 "TMI-2 Lessons Learned Task Force Status Report and Short Term Recommen-da tions".' Babcock and Wilcox (B&W) undertook this investigation at the request of the B&W Owners Group.
On January 31, 1980 (Serial No. 587) a preliminary evaluation of a reactor coolant hot leg level instrument identified this potential device as ambiguous and confusing to a point of leading the operators to incorrect interpretations of core conditions during a severe incident. This submittal also identified a continuing review of other conceptual approaches. This review is now completed and five copies of the " Evaluation of Instrumentation to Detect Inade.quate Core Cooling Prepared for 177 Owners Group" dated August 15, 1980 are enclosed.
The conclusions of this evaluation identify subcooling monitors and incore thermocouples as appropriate instrumentation for detection of inadequate core cooling at our facility. These instruments exist at Davis-Besse Unit 1 and operator guidelines are in place for their use. Toledo Edison considers this to meet the recommendation of section 2.1.3.b of NUREG 0578 of "unabmiguous, easy-to-interpret indication of inadequate core cooling."
Very truly fours,
\\
I RPC:TJM:SCJ: sic
\\
cc: NRC D-B Resident Inspector
{
THE TCLECO ECISON COMPANY EDISON PLAZA 3CO MADISCN AVENUE TCLEDO, CHIO 43652 8 00010 0/M
hocht un co-3%
l~
24m po uPV-3 l
O M MO "pi C E l V'EE W E,1910 AUG 191980 i
POWER ENG.
1 EVALUATION OF INSTRUMENTATION TO DETECT INADEQUATE CORE COOLING PREPARED FOR
\\
177 OWNERS GROUP Issued:
August 15, 1980 Document No:
R6 11?nR99_nn Contract No/ File gap.7113 Prepared By Reviewed By Wh gy fJ p Reieased By
- Lu m p1)'y f o %
DUPLICATE DOCUMENT BabCC Nuclear Powe Entire document previously P. C entered into system under:
Lynchb hOkh3Ohhb ANO
- 0. a a No. of pages:
-