ML19312C622
| ML19312C622 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 04/21/1978 |
| From: | Parker W DUKE POWER CO. |
| To: | Case E, Reid R Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 7912190816 | |
| Download: ML19312C622 (3) | |
Text
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04 (21 n 2 REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)
DISTRIBUTION FOR INCOMING MATERIAL 50-260/270/287 REC: CASE E G ORG: PARKER W O DOCDATE: 04/21/78 NRC DUKE PWR DATE RCVD: 04/26/78 DOCTYPE: LETTER NOTARIZED: NO COPIES RECEIVED SUDJECT:
LTR 1 ENCL 0 FURNISHING ADDL INFO RE APPLICANT"S LTR DTD 04/14/78 CONCERNING APPARENT ERROR IN THE BbW SMALL BREAK ECCS ANALYSIS APPLICABLE TO SUBJECT FACILITY &
CORRECTIVE ACTIONS IMPLEMENTED.
ADVISING f.PPLICANT CONSIDERS UNITS CAN BE OPERATED AT FULL RATED PWR SAFELY PLANT NAME:OCONEE - UNIT 1 REVIEWER INITI AL:
XJM OCONEE - UNIT 2 DISTRIBUTER INITIAL: p(_
OCONEE - UNIT 3
- DISTRIBUTION OF THIS MATERIAL IS AS FOLLOWS ***************+**
NOTES:
1.
M CUNNINGHAM - ALL AMENDMENTS TO FSAR AND CHANGES TO TECH SPECS GENERAL DISTRIBUTION FOR AFTER ISSUANCE OF OPERATING LICENSE.
(DISTRIBUTION CODE A001)
FOR ACTION:
By_f' " Er ^E ' n - =' TR ONLY(7)
INTERNAL:
(
REG FILE **LTR ON'V NRC PDR**LTR ONLY(1) i a be*LTR ONLY(2)
OELD**LTR ONLY(1)
HANAUER**LTR ONLY(1)
CHECK **LTR ONLY(1)
EISENHUT**LTR ONLY(1)
SHAO**LTR ONLY(1)
BAER**LTR ONLY(1)
BUTLER **LTR ONLY(1)
EEB**LTR ONLY(1)
J COLLINS **LTR ONLY(1)
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MCGOUGH**LTR ONLY(1)
EXTERNAL LPDR'S WALHALLA, SC**LTR ONLY(1)
TIC **LTR ONLY(1)
NSIC**LTR ONLY(1)
ACRS CAT B**LTR ONLY(16)
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DISTRIBUTION:
LTR 40 ENCL 0 CONTROL NBR:
781160180 SIZE: 2P c
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- THE END
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DUKE POWER COMPMY Powtu Berunno 402 Sorin Curwen STarrT, CnAumTTr. N. C. asa.a w w u aw e....ca.sn.
April 21, 1978 d
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7 3*3-4382 Mr. Edson G. Case, Acting Director pg f
Office of Nuclear Reactor Regulation
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U. S. Nuclear Regulatory Commission S
- 2. _
Washington, D. C.
20555 N
E
~
w
.U' wJ Attention:
Mr. R. Reid, Chief Operating Reactors Branch #4
Reference:
Oconee Nuclear Station Docket Nos. 50-269, -270, -287
Dear Sir:
[,,[,,l,, g,,, L, g, y, " ((,.; (((i My letter of April 14, 1978 addressed an apparent error in the B&W small break ECCS analysis applicable to Oconee Nuclear Station and corrective actions which had been implemented to assure continued safe operation of the Oconee units.
Subsequently, several communica-tions have occurred invclving Duke, B&W, and the staff with regard to the results of additional small break ECCS analyses.
Specifically, B&W evaluations performed during the week of April 16, 1978 indicated results more severe than those addressed by my letter of April 14, 1978.
This letter is to summarize our current understanding with regard to this matter and to provide certain pertinent information to the staff.
Based on our communications with the Oconee NSSS and fuel vendor, B&W, it is our understanding and position that Oconee can continue to be operated at full rated power (2568 MWt core power) safely and in full compliance with the provisions of 10CFR50.46.
In order to assure this, however, certain prompt operator actions would be required following a postulated small break LOCA, assuming various worst case single failures.
Specifically, the HPI pump B-C discharge header cross-over valves (HP-ll6 and HP-ll7) and the HPI injection line A engineered safe-guards valve (HP-26) must begin opening within five minutes of actuation of the engineered safeguards system and must be fully open within an additional ten minutes.
Procedures have been established to assure that this requirement is met.
This, in turn, assures that adequate timely flow to the core is provided.
In addition to the amendment proposed by our letter of April 20, 1978, a facility operating license amendment will be submitted by May 1, 1978 to require the procedures necessary to implement the actions discussed I
hgD'i, 0
b Mr. Edson G. Case, Acting Director Page Two April 21, 1978 above. Also, as soon as the ir: formation is finalized and available, a submittal with regard to the B&W small break ECCS analysis will be pro-vided, to include:
Break spectrum information; identification of worst case break; justification of peak clad temperatures if core uncovery occurs; and justification of any necessary operator actions.
It is also our intent to submit within three months (i.e., by July 21, 1978), pro-posed corrective action for the particular incident of present concern which will place less reliance on a high state of operator readiness.
(It is our intention to demonstrate that the time available for operator action is equivalent to that indicated in my letter of April 14, 1978 -
i.e., 25 minutes.).
In conclusion, we continue to consider that the Oconee units can be operated at full rated power safely and in compliance with the provisions of 10CFR 50.46.
Very truly yours, W
/
^
l William O. Parker, Jr.
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