ML20073R664
| ML20073R664 | |
| Person / Time | |
|---|---|
| Site: | Mcguire |
| Issue date: | 04/28/1983 |
| From: | Tucker H DUKE POWER CO. |
| To: | Adensam E, Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8305040469 | |
| Download: ML20073R664 (2) | |
Text
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DUKE POWER GOMPANY P.O. nox 33180 CHAllLOTTit, N.O. 28242
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April 28, 1983
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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:
My letter of February 18, 1983 provided responses and clarifications to several items that the NRC had requested informally. Among the items addressed was "B C 4
Control Rod Surveillance", in which the NRC staff had expressed concern over potential boron leaching from the B4C pellets encapsulated in the Unit 2 control rods. Duke stated that we will verify reactivity worth on all control banks including the shutdown banks during initial physics testing and during startup physics testing following the first refueling shutdown. However, under the McGuire Technical Specifications it is not possible to measure all rod banks for McGuire 2 initial startup.
In approving use of the hybrid control rods, the NRC placed three requirements on Westinghouse for physics testing and surveillance of these rods. They are:
- 1) measurement of all bank worths each cycle, 2) several worth checks throughout the first cycle, and 3) visual examination of the rods after three cycles.
For McGuire 2 Cycle 1 Zero Power Physics Testing, Duke intends to perform measure-ment of all banks (by boron addition or dilution) except shutdown banks A and B, as was done on McGuire 1 Cycle 1.
The Westinghouse rod swap topical report, which would allow measurement of all banks using rod swap, has not yet received a SER from the NRC and therefore cannot be used. After the worth of shutdown bank C has been determined, shutdown bank B and part of shutdown bank A will be " swapped" with the highest worth stuck rod. After this rod swap is performed shutdown bank A vill be diluted, and a " boron endpoint" performed with the remaining portion of shutdown bank A.
From the information obtained, the worth of all rods minus the highest worth stuck rod is calculated (must be within 110% of predicted). Also the boron concentration with a]'
'c in minus the highest worth stuck rod is calculated (must be within 150 ppm or predicted). It should be noted that this is the way Westinghouse compares rod worths determined by dilution to rod worths determined by rod swap in WCAP-9863, " Rod Bank Worth Measurements Utilizing Bank Exchange".
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Harold R. Denton April 28, 1983 Page 2 For reload testing we expect to initially measure all banks using rod swap. Duke will be reviewing all physics test measurement programs and may be recommending reductions in these programs in the future.
Such reduced scope programs will be developed consistent with industry standards, Duke experience, and merit of per-forming the particular measurement.
Estimated critical positions (ECPs) will be used throughout Cycle 1 to satisfy the worth check requirements. A visual inspection of the hybrid control rods will be performed after the third cycle of operation, as required by the SER.
If there are any questions regarding this matter, please advise.
Very truly yours, c' /k ( :.-
al B. Tucker PBN:jfw i
cc:
Mr. James P. O'Reilly, Regional Administrator U. S. Nuclear Regulatory Commission Region II 4
101 Marietta Street, Suite 2900 Atlanta, Georgia 30303 Mr. W. T. Orders l
NRC Resident Inspector McGuire Nuclear Station l-l l
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