ML20083B227
| ML20083B227 | |
| Person / Time | |
|---|---|
| Site: | McGuire, Mcguire  |
| Issue date: | 12/15/1983 |
| From: | Tucker H DUKE POWER CO. |
| To: | Adensam E, Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| TAC-53214, TAC-53215, NUDOCS 8312200572 | |
| Download: ML20083B227 (2) | |
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DuxE POWER GOMPANY P.O. BOX 33180 CHARLOTrE, N.C. 98949 MALB. TUCKER Tatarssown E= -- -
December 15, 1983 Mr. Harold R. Denton, Director
. Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Washington, D. C. 20555 Attention:
Ms. E. G. Adensam, Chief Licensing Branch No. 4 Re:.McGuire Nuclear Station Docket Nos.- 50-369. 50-370
Dear Mr. Denton:
'My letter of November 18 1983 transmitted proposed amendments to Facility Operating Licenses NPF-9.and NPF-17 which would reduce the minimum Reactor Coolant System (RCS) flow rate for_ Unit 2.
Proposed Technical Specification changes;were also provided..This letter also requested that this amendment be issued under the emergency provisions of 10 CFR 50,91 since, in our view, the circumstances exist to justify such treatment, namely, 1) Unit 2 is derated.to 90% power and 2) timely action was taken to apply for.the change.
There is a perception within the Staff that Duke Power Company should have recognized the need,for this change'over a year ago and should have taken action at that time tcirevise the RCS flow requirements on Unit'2.
In fact, the problem with low RCS flow was recognized several years.ago and a change to the McGuire Unit:1 Technical Specific'ations was requested by Duke and authorized by the NRC in November 1981 which' enabled Unit 1 to continue operating at 90% power. Mais change.. Amendment 9 to.NPF-9, allowed McGuire
, Unit 1 to operate at 90% power until~ additional analysis could be done to justify a. lower minimum flow rate.
'On. November 23, 1982 Duke requested a change to the McGuire Unit 1 Technical Specifications which lowered the minimum RCS flow requirements by reducing the uncertainty in the flow measurement from 3.5% to 1.8%.
At the time of this submittal.. Unit 2 was not licensed.. This change was issued as Amendment 22 to NPF-9 (Unit 1) and Amendment 3 to NPF-17 (Unit 2), Unit 2 having received an operating license in the-interval between the amendment request and issuance.
"This change allowed Unit 1 to operate at full power and there was every expecta-
- tion that Unit 2 could likewise operate at full power.
The first valid. flow measurement was made on Unit 2 after escalation to 75%
-power.
RCS flow measurements _made by the precision heat balance method are not generally made at power levels less than about.75% due to reduced accuracy.
McGuire Unit 2 initially achieved 75% RTP on-September 10, 1983,'and a precision
-heat balance' measurement complete'd on' September 13, 1983 provided the first SCOl f>hbD 0
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'Mr.' Harold R. Denton,' Director December 15', 1983' Page-2 4
1 indication of low RCS flow -- 390,300 gpm. RCS flow measurements completed on October 12, 1983 while at 90% RTP' indicated 392,500 gpm total, flow. McGuire LUnit'2 coupleted the required startup testing for power ascension above 90%
RTP on October 12, 1983 and has been derated since that date. After the low flow condition was identified, Duke Power initiated' efforts to evaluate a proposed reduction in the RCS flow requirements; this safety evaluation was essentially completed on November 10, 1983.
Even1though over three weeks have elapsed since our initial submittal on
(. c November 18, 1983,' Duke Power still requests emergency consideration. Unit 2
- has not operated at full power and a, planned outage is scheduled for December 23,
'1983. ! Approval of the requested amendment would allow check-out of Unit 2 performance prior to the outage and would allow any deficiencies noted to be
. corrected lduring.the. outage. Also, additional startup testing is required at full power including a full power unit trip. This evolution could be performed as.an entry into the-planned outage.
- Please advise if there are any further questions regarding this matter. Your prompt attention to this matter would be appreciated.
i Very truly yours,
...d
$,u Hal'B. Tucker
'GAC/php cc:
Mr.
W.~ T. Orders NRC Resident Inspector McGuire Nuclear Station Mr.: James P. O'Reilly,' Regional Administrator U. S. Nuclear Regulatory Commission Region II'
'101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30303 i
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