ML20071D158
| ML20071D158 | |
| Person / Time | |
|---|---|
| Site: | Mcguire |
| Issue date: | 02/28/1983 |
| From: | Tucker H DUKE POWER CO. |
| To: | Adensam E, Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8303090214 | |
| Download: ML20071D158 (3) | |
Text
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DUKE POWER GOMPANY P.O. BOX 33180 CHARLOTTE, N.C. 28242 HAL B. TUCKER TELzenoxz February 28, 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 Unit 2 Docket No. 50-370
Dear Mr. Denton:
On January 17, 1983, the Commission omended its regulation concerning the environmental qualification of electric equipment important to safety for nuclear power plants, 10 CFR 550.49. This amendment became effective on February 22, 1983. As pertinent hereto, Section 50.49(1) requires that (i) Applicants for operating licenses that are to be granted on or after February 22, 1983, but prior to November 30, 1985, shall perform an analysis to ensure that the plant can be safely operated pending completion of equipment qualification required by this section.
This analysis must be submitted to the Director of the Office of Nuc1 car Reactor legulation for consideration prior to the granting of an operating license...
Duke Power Company is an applicant for the William B. McGuire Nuclear Station, Unit 2 operating license. Duke anticipates that it will receive a 5% power operating license on March 1, 1983; receipt of a full power license is antici-pated on May 19, 1983. Duke is in the process of completing the qualification of equipment required by Section 50.49.
Duke has previously provided information to the NRC concerning the status of equipment qualification by letters of February 23 and February 25, 1983. The present schedule calls for the completion of this qualification effort within the next several months. Accordingly, in order to obtain the McGuire Unit 2 onerating license, Duke is required by Section 50.49(i) to perform an analysis to " ensure that the plant can be safely operated" pending completion of the above referenced qualification of equipment.
Duke believes this justification can be provided in two steps, i.e., a 5% power j
justification and a full power justification.
Inasmuch as the license that Duke anticipates receiving on March 1, 1983 will be a 5% power operating license, Duke today provides a justification that McGuire Unit 2 can be safety operated up to a 5% powet level pending completion of the equipment qualification required by Section 50.49(i).
This justification, in the form of analysis, is provided i
EKPD3090214 830228 PDR ADOCK 05000370 A
~1 Mr. Harold R.'Dentcn, Dir ctcr February 28, 1983 Page 2
.in Attachment 1.
Duke is of the view that such analysis demonstrates that
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the provisions of-Section 50.49(i) have been met with respect to operation at power levels not t o exceed 5%.
Prior to receipt of authorization to exceed 5% power operation, Duke will" provide a further analysis which will demonstrate, to the satisfaction of Section 50.49(1),
that McGuire Unit 2 can operate safely up to full power level pending completion-of equipment qualification required by Section 50.49.
Duke believes that the two-step justification fully conforms to the requirement of Section 50.49(i).
Very truly yours,
,i
- (/ B. ? M y g' g Hal B. Tucker 1
j GAC/php Attachment 5
Mr. James P. O'Reilly, Regional Administrator cc:
j U. S. Nuclear Regulatory Commission Region II 101 Marietta Street Suite 3100 Atlanta, Georgia 30303 4
3 4
Mr. W. T. Orders j
NRC Resident Inspector i
McGuire Nuclear Station i
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McGuire Nuclear Station L
Analysis of Plant' Operation / ssuming A
Certain Accident Scenarios - under. 5% - ' License 1
Zero-power: physics testing at McGuire UnitL 2 nominally includes operation at 3% power for four to six hours. -Assuming an accident to occur at the end of n
a six' hour period would therefore be.the most limiting-scenario from a decay; heat' point of view. Decay power-immediately following reactor trip is about 6 mw and has decreased by almost a factor of ten in one hour. After one day F
- the residual power level is extremely small--approximately 40 kw--while the total-integrated _ heat input to the coolant during this 24. hour period is 14.3 million BTUs.
j-Two limiting accident scenarios were analyzed, a large loss-of-coolant accident-4 (LOCA) with no emergency core cooling system (ECCS) available and a complete
- loss of all feedwater with no ECCS.
i For the LOCA case, with only cold leg accumulators injecting, about 26'O ft3 of liquid-would remain above the top of the core. Assuming an adiabatic heatup 7 BTUs p
of this water from saturated conditions at atmospheric pressure, 1.5 x 10 are needed to boil this inventory away. Since this amount of heat will not
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have been added in the first 24-hours, more than'one day would be available for damage control measures to be~taken to ensure core cooling.
For the loss of all feedwater with no ECCS scenario the reactor coolant system (RCS) would pressurize to the pressurizer safety valve setpoint (2500 psia) and inventory would be relieved through the valves both as steam and liquid. The i
amount of power required to heat the RCS (excluding inventory in the-pressurizer)
I from no-load conditions of 2250 paia and 557 F to saturation at 2250 psia is j-5.4 x 107 BTUs. Although there will be some water relief due to thermal expansion of the coolant as it is heated, this can be safely neglected since the amount of 4
heat generated in the first 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> is almost four times less than that required to heat the inventory to saturation. The actual time to uncover the core would be greater since 1) the inventory would have to be further heated to saturation at 2500 psia and then boiled away; and 2) the steam generator secondary side i
inventory would have to be boiled off before the adiabatic heatup could begin.
i-Thus, the large LOCA is seen to be the limiting accident from a core cooling standpoint.
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In summary, assuming the limiting accident (LOCA) were to occur during physics testing, more than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> are available to correct any equipment deficiencies which could interrupt core cooling.
Since the only activity planned under the 2
i 5% license is physics testing, the plant can be operated safely pending completion of equipment qualification.
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