ML20107G437
| ML20107G437 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 10/23/1984 |
| From: | Tucker H DUKE POWER CO. |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| IEB-84-03, IEB-84-3, NUDOCS 8411080043 | |
| Download: ML20107G437 (2) | |
Text
O.
hou DUKE POWER GOMPANY P.O. BOX 33180 CHARLOTTE, N.C. 28242 Q{-
HALB. TUCKER e
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3tl 005 October 23, 1984
-Ur. James P. O'Reilly,' Regional Administrator U. S. Nuclear Regulatory Commission Region II 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323 Re: Oconee Nuclear Station-Docket Nos. 50-269, -270, -287 IE Bulletin 84-03
Dear Sir:
By letter dated September 26, 1984, Duke Power Company reeponded to IE Bulletin 84-03 concerning the recent failure of the refueling cavity water seal and the rapid draining of the refueling cavity at the Haddam
-Neck Plant.- Duke Power concluded that considering the different design of the seal plate and gasket configuration at Oconee, a gross seal failure of the magnitude described in IE Bulletin 84-03 is not a credible event at Oconee.
In the unlikely event of a totally dislodged inner seal, a leak rate of less than 50 gpm would be expected from the Refueling Canal.
Also, instrumentation and procedures currently in place to detect and respond to unexplained water loss in the Spent Fuel Pool and Refueling Canal ensures that such an event would be detected and mitigated.
The purpose of this letter is to provide additional information requested
.by the NRC/01E Region II Staff during a telephone conversation on October 12, 1984. The specific information requested concerned certain procedures, training and instrumentation to detect and mitigate events similar to that deacribed in IE Bulletin 84-03.
The following paragraphs address the requested information and supplement our original response to IE Bulletin 84-03 dated September 26, 1984.
- 1) In the event of an unexplained decrease of the water level in the Fuel Transfer Canal, the refueling procedure requires closing of the Fuel Transfer Tubes Isolation valves SF1, SF2 and SFP.
- 2) Operating procedures for the Spent Fuel Cooling System adequately address makeup to the Spent Fuel Pool and Transfer Canal. Procedures include pool level makeup from CBAST, BAMT, BHUT and CBAST by Bleed Transfer Pump. These procedures will ensure that necessary actions are taken to restore the water level to the spent fuel pool and fuel transfer canal.
The same procedures require sampling of the system for boron concentration twenty-four hours after completion of makeup. Additionally, Emergency procedures for Boron Dilution for Case A Reactor Vessel Head Removal and unexplained neutron level increase require a boron sample and boron addition if necessary.
g4 1000043 841023 cn 05000
$$//
Mr... James P. O'Reilly, RSgion 1 Administrator j
October 23, 1984 Page Two-1
.3)
In regard to the training associated with loss of level, operators are qualified with respect to procedures and-receive training during requalification.
- 4) In the event of a decrease of Spent Fuel Pool level, one or more of the following indications are available to the operators to detect and mitigate the event:
a)_ High Level Alarm from Normal Sumps (15" or about 220 gallons) b) Trend Chart on normal sump c) Spent Fuel Level Indication STAT Alarm d)- Indication by visual inspection (tours)
Upon indication of loss of level by any of the above methods, the procedures require an investigation of the cause of the eve..t and the appropriate corrective actions are taken immediately.
Based _on the information provided in this letter, which supplements the original submittal of September 26, 1984, Duke concludes that adequate procedures are in place to assure an appropriate response to unexplained water Joss in the spent fuel pool and refueling. canal. The current systems are capable of mitigating the consequences of the postulated failure of the reactor cavity water seal.
I declare under ;senalty of perjury that the information contained herein is correct to the best of my knowledge as executed on October 23, 1984.
Very truly yours,
(
// '
g_
s e-Hal B. Tucker MAH:slb Attachment cc: Document Control Desk-Mr. J. C. Bryant U. S. Nuclear Regulatory Commission NRC Resident Inspector Washington, D. C.
20555 Oconee Nuclear Station Ms. Helen Nicolaras Office of Nuclear Reactor Regulatioi U. S. Nuclear Regulatory Commission Washington, D. C.
20555