ML20058K855
| ML20058K855 | |
| Person / Time | |
|---|---|
| Site: | Monticello  |
| Issue date: | 04/19/1973 |
| From: | Mayer L NORTHERN STATES POWER CO. |
| To: | Oleary J US ATOMIC ENERGY COMMISSION (AEC) |
| References | |
| NUDOCS 9104250453 | |
| Download: ML20058K855 (2) | |
Text
.
t
.g Fila Cy?
T9-~ htery NORTHERN STATES POWER COMPANY Minneapolis, Minnesota 55401 1
N i I / 0A o
April 19, 1973 e
- {/l p\\
) yj l r ?,
i, Fr.' 3 0 APff, ' sl, 2a y,8 _
tH Mr. John F. O' Leary, Director s
Directorate of Licensing United States Atomic Energy Commission
/g
- y. '
Washington, D C 20545
- r,
y i.
Dear Mr. O' Leary:
hDNTICELLO NUCLFAR GENERATING PLAhT Docket No. 50-263 License No. DPR-22 RHR Service Water Pump Seal Problem A condition occurred at the hbnticello Nuclear Generating Plant recently which we are reporting to your office in acconlance with the provisions of Section 6,6.C.1 of Appendix A, Technical Specifications, of the Provisional Operating License DPR-22.
On March 23, 1973, while operating #11 RHR Service Water pump for shutdown cooling, smoke was observed coming from the pump. An investigation of the problem revealed that the upper gland seal packing on the pump had overheated due to dirt in the upper packing (see Figure attached). Cooling water for the bushing is provided by river water from the discharge of the pump. The upper and lower sets of packing are cooled by well water injected at a pressure of approximately 50 psig. hhen the pump is operated at low flow rates, with corresponding high discharge pressures, unfiltered river water is forced back into the upper seal cavity.
Prolonged operation under such conditions resulted in the dirt accumulation.
The upper seal packing was replaced and adjusted. hbdifications to eliminate the problem are being evaluated. Operation of RHR service water pumps at low flow rates is not required and will not be conducted until such modifications are implemented.
4 Yours very truly, A
L 0 Mayer, PE
- 8:
APR261973
- h
~
Director of Nuclear Support Services EEGULATORY 1,
w1 stcDON N*
J IDM/kik m3G w
cc: B H Grier m
G Charnoff Minnesota Pollution Control Agency ATEN: Ken Drugan 9104250453 730419 attachment CF ADOCK 05000263 CF
4 fr
]
b I
9 i
l y,'
PROVING *'/
h LE AL WATER INLET f
\\
N e-7 r
N
/
BLEE D OFF LINE
\\
/
/
% kj
-i N
\\
l Bus H nn tr-5 3
(
x 4
i
\\
-+ Pump DISCH ARG E.
s
~
RHR SERVICE WEiER 9WMP SE6L W6TER BRR ANG EMEIVT 1