ML20079F158
| ML20079F158 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 01/12/1984 |
| From: | Carey J DUQUESNE LIGHT CO. |
| To: | Varga S Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8401180129 | |
| Download: ML20079F158 (3) | |
Text
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Telephone (412) 393-6000 Nuclear Division P.O. Box 4 Shippingport, PA 15077 0004 January 12, 1984 Director of fluciear Reactor Regulation United States lluclear Regulatory Commission Attn:
fdr. Steven A. Varga, Chief Operating Reactors Branch flo.1 Division of Licensing Washington, DC 20555
Reference:
Beaver Valley Power Station, Unit flo.1 Docket flo. 50-334, License flo. DPR-66 Appendix R to 10 CFR 50 Thermocouples vs. Hot Leg Temperature Gentlemen:
This letter is provided to document the understanding reached between your Auxiliary Systems Branch staff reviewers and Duquesne Light Company personnel per telecon on January 9,1984. This confer-ence call was made tc review our position on Appendix R to 10CFR50, Section III.L.2 and provide wide-range core exit thermocouples (CETC) as an acceptable alternative to wide-range T loop RTDs for required g
process monitoring capability Beaver Valley Power Station, Unit 1 Safety Evaluatica Report (SER) for Appendix R to 10CFR50, Items III.G and III,L was published on January 5,1983.
The SER documented the requirement for hot leg temper-ature RTDs at our Backup Indication Panel (BIP) for providing indication of the degree of subcooling when used in conjunction with RCS pressure. This process monitoring capability was previously committed to in our letter of December 10, 1982 based on discussions with your staff at that time.
Since then, we understand that the staff has agreed to wide-range CETC as an ac-ceptable alternative to the wide-range Tu loop RTDs as documented in an interoffice memorandum between R. J. f'atYson and L. S. Rubenstein dated fia rch 18, 1983 and conrirmed in our phone conversation with your staff on Jancy 9,1984.
The selection of the four (4) CETCs as shown on the attached Figure
" Core Exit Themoccuple Locations" were chosen to give an indication of the average tempergre reading representative of T.
Through past evalua-H tions and analyses performed by the Westinghouse Owner's Group on the issue of Reactor Vessel voiding under natural circulation condigns, it has been shown that voiding is not a significant safety concern This is due, in part to the fact that these voids tend to collapse as they i
come into contact with the subcooled regions in the system.
In the un-likely event that any hypothetical void did expand into the upper portion of the hot legs, this void would be collapsed by the subcooled liquid in the hot legs or condensed in the steam generator plenum and tubes. There-fore, the CETC indication would not be subject to this concern.
8401180129 840112 I
E DV PDR ADOCK 05000334 F
Beaver Valley Power Station, Unit No.1 Docket No. 50-334, License No. DPR-66 Appendix R to 10 CFR 50 Thermocouples vs. Hot Leg Temperature Page 2 The procedures that will be prepared for safe shutdown from the BIP will preclude significant voiding in the vessel head by limiting the cool-oown rate of the system nd maintaining a high subcooling margin.
Therefore, our intention is to use CETCs indication vs. T at our BIP for meeting the applicable requirement of Section III.L.2 of A pendix R.
Please contact us if additional information or clarification is necessa ry.
Ver tr y yours,
?
Carey Vice President, Nuclear References U)WFLASH Code (2) Summary Report 0G-57 dated April 20, 1981 forwarded to the NRC cc: Mr. W. M. Troskoski, Resident Inspector U. S. Nuclear Regulatory Commission Beaver Vc11ey Power Station Shippingport, PA 15077 U. S. Nuclear Regulatory Commission c/o Document Managment Branch Washington, DC 20555 Director, Safety Evaluation & Control Virginia Electric & Power Company P.O. Box 26666 One James River Plaza Richmond, VA 23261
FIGURE I
" Core Exit Thennocouple Locations"
.I 2
3 4
5 6
7 8
9 10 11 12 13 I4 15 3
I 1
LOOP C g A
T-l B
T
.2.
T-3 i
G N
Tzr T-28 W
,r (F29 0
T30 E
TV
(
T-s T-3I T32 T-6 T-7 F
T-8 T-9 T-io T-il T-33 7
N' G
T-12 TBy T-13 T-35 T-36 f
f Ff0 f H
T-37 T-33 T-IV F39 T-Y/
T-/5 LOOP E a
Tib.
T-17 T-18 k
K-T-19 T-20 F21 T22
^
{ FY3,)
L y T-Y2 T-YY FYE M
FYb T25 T-97 l
T-48 T 24 T-41 T-50 N-P
^
vsI T-25 R
P26 LOOP A I
l A'
l T
inacates incere ener:ocouple location.
BIP Thermocouples:
T-29 T-40 T-38 T-43
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