ML19347D501
| ML19347D501 | |
| Person / Time | |
|---|---|
| Site: | Summer  |
| Issue date: | 03/20/1981 |
| From: | Nichols T SOUTH CAROLINA ELECTRIC & GAS CO. |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8103260275 | |
| Download: ML19347D501 (2) | |
Text
{{#Wiki_filter:' F e SOUTH CAROLINA ELECTRIC & GAS COMPANY Post orrier son re4 CotuMe:A. south CAROLINA 29218 T.C.NICHOL5.JR. we p.... c c.ccor~c March 20, 1981 me ouer......... o.c in#,. g 4 (. s, .e c.% a # If, %g / Mr. Harold R. Denton, Director 4 Office of Nuclear Reactor Geulation bi .s U. S. Nuclear Regulatory Commission Q / Washington, D. C. 20555 4Q \\
Subject:
Virgil C. Summer Nuclear Station Docket No. 50/395 Boron Dilution Event - FSAR
Dear Mr. Denton:
In FSAR Amendment 24. the attached page 15.2-22b was mistakenly renamed and a new page 15.2-22b was added. The page which was renamed will be added back into the FSAR in the next amendment to bridge the information currently found on pages 15.2-22b and 15.2-23. If you have any questions, please let us know. Very truly yours, T. C. Nichols, Jr. RC:TCN:pj Attachment I CC: V. C. Summer w/o att. l G. H. Fischer w/o att. T. C. Nichols, Jr. w/o att. C. A. Price D. A. Nauman W. A; Williams, Jr. i R. B. Clary A. R. Koon A. A. Smith. H. N. Cyrus J. B. Knotts, Jr. J. L. Skolds B. A. Bursey O. S. Bradham ISEG NPCF/Whitaker File PRS 8108260,275 j
Dilution flow is assumed to be a naximirm of 150 gpm, which is the ~ capability of one primary water ir.akeup pump to deliver unborated p,(' ) water to the PCS, A mininum RCS water volume of 5000 ft3 is used. This is a conser-vative estimate of the active RCS volume with one reactor coolant 23 s ) pump operating. 4. Dilution During Startup T .,/ Prior to startup, the RCS is filled with borated water at a bcron concentration of 1555 ppa. This is a conservative estimate with the reactor at a 1.77% Ak/k shutdown margin at 5570F, Core monitoring is by external BF3 detectors. Mixing of the reac-tor coolant is acce.nplished by operation of the reictor coolant pumps. High source range flux level ara all reactor trip alarms are effective. ,(, In the analysis, a conservatively high dilution flow capacity for the centrifugal charging pumps is considered (approximately 300 spm). A minimum volume of 7360 ft3 in the reactor coolant system 23 is used. This corresponds to the active volume of the RCS excluding the pressurizer.
- 5.. Dilution During Full Power Operation 23 the dilution rate is k'i th the unit at power _ and the RCS at pressure,
( limited by the capacity of the charging valve (analysis is performed assuming two charging pumps are in operation although only 23 (? *. s_. -{f 15.2-22b AMENDM?.NT 23 J ant'ARY, 1981}}