ML20090D311
| ML20090D311 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 10/26/1973 |
| From: | Schneider R NIAGARA MOHAWK POWER CORP. |
| To: | Skovholt D US ATOMIC ENERGY COMMISSION (AEC) |
| References | |
| NUDOCS 8302280008 | |
| Download: ML20090D311 (5) | |
Text
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NIAGARA MOHAWK POWF.R CORPORATION NIAGARA MOHAWK 300 ERIE BOULEVARD WEST SYRACUSE.se Y 13202 October 26, 1973 O
c4 Mr. Donald J. Skovholt fi. p. 'O p
4' Assistant Director for Reactor Operations I h
-3 Division of Reactor Licensing Y Ng 8
United States Atomic Energy Commission S-DA
- F Washington, D. C.
20545 dgu.;y e%
o Re: Provisional Operating License: DPR-17 Docket No.:
50-220
'4
Dear Mr. Skovholt:
On October 18, 1973, the Nine Mile Point Unit #1 reactor was shut down, the result of an increasing rate of unidentifiable leakage in the drywell.
The shutdown, which occurred during the routine RO:I AEC Inspection, provided the opportunity to perform the following:
1.
Shutdown Margin Demonstrations - in acco' dance with your letter r
l dated September 25, 1973.
2.
Inspections of hydraulic shock suppressors in response to your request on October 1, 19732 and RO:I telephoned request 3 on July 26, 1973.
3.
The leak test of the manhole cover on the drywell which was committed in our letter of October 10, 1973 in response to your 1ctter of 4
5 September 28, 1973,
om On August l'7,1973 leakage into the Drywell Floor Drain Tank (DNFDT) had onio increased to 2.5 gpm.
Reactor Recirculation Pump 12 (RRP 12) was the immediate 88 suspect as equalization was occurring between the low and high pressure seal.
]
Once RRP 12 was secured the DWFDT leakage decreased to less than.25 gpm.
In 86 On October 1,1973, with RRP 12 still secure leakage again was gradually increasing to the DWFDT. With leakage approaching 2.8 gpm on October 6, ry 1973 Station Supervision ordered increased surveillance on the DNFDT leakage.
Although Technical Specifications call for a check of Icakage only once per om
@,n.
day, it was deemed necessary to continually plot leakage each hour to note trends or other indications which could provide an insight into the source of Icakage. The Radiation Protection and Chemistry section had aircady determined that the major percentage of Icaking liquid was not reactor coolant.
On October 18, 1973 with DNFDT Icakage indicating approximately 4.5 gpa, Plant Supervision ordered the reactor shutdown.
During the subsequent drywell inspec-tion the source of Icakage was identified as steam Icaks thru the valve packing on two electromatic relief systems blocking valves and a s.
11 leak on RRP 12 seal.
- - ~ - - - - - - ' -
U.S. Atomic Energy ommission g
j W
During the shutdown and at Xenen free condition the shutdown margin demonstrations were performed. All control rods were verified to meet the minimum shutdown margin of 0.0075 delta k/k at cold, xenon free, operating samarium conditions.
A complete report including responses to your question is being readied and will be sent to you prior to December 4,1973 as outlined l
in your letter.
An inspection of the hydraulic shock suppressors was made during the shutde:m. to this letter details' the manufacturer, number of snubbers, identification of low fluid reservoirs, and corrective actions taken.
In summary, no defective seals were found and no shock suppressors were found to be void of fluid. A certain amount of leakage was found from a few suppressors, the result of loose reservoir connections.
Also during the shutdown, the manhole cover on the drywell was leak tested. The penetration was pressurized to 35 psig and the decay in pressure noted over one half hour. No loss of pressure was observed.
Very truly yours, SdolphR.Schnl eider 1
Yice President - Electric Operations RRS:cm 1.
Ltr. Skovholt - Raymond Sept. 25, 1973
+
2.
Ltr. Skovholt - Raymond Oct. 1, 1973 3.
Tph. Cantrell - Perkins July 26, 1973 4.
Ltr. Schneider- 0'Reilly Oct. 10, 1973 S.
Ltr. Skovholt - Schneider Sept. 28, 1973 e
l l
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ENCLOSURE 1 HYDRAULIC SHOCK SUPPRESSOR 1.
Manufacturer: All Grinnell Manufacturer 2.
Number of Snubbers:
110 Fluid SF-96-1000 3.
Where fluid was added the connection that was leaking was tightened.
4.
Serial #
System Condition Corrective Action 1367-D2
- Elec. Vent Lines Good 1438-D2 Elec. Vent Lines Good 1188-D2 Elec. Vent Lines Good 1195-D2 Elec. Vent Lines Good 1463-D2 Elec. Vent Lines Good 1372-D2 Elec. Vent Lines Good 1340- D2 Elec. Vent Lines Good 1207-D2 Elec. Vent Lines Good 1459-D2 Elec. Vent Lines Good 1200- D2 Elec. Vent Lines Good 1454-D2 Elec. Vent Lines Good
- 1491-D3 Elec. Vent Lines Good 1344 Elec. Vent Lines Good
~
3450- D2 Elec. Vent Lines' Good 1488-D3 Elec. Vent Lines Good 1495-D3 Elec. Vent Lines Low oil in Res.
Added Fluid 1026-D3 Elec. Vent Lines Good 1028-D3 Elec. Vent Lines Good 1494-D3 Elec. Vent Lines Low oil in Res.
Added Fluid 1217-D2 Elec. Vent Lines Good 1350- D2 Elec. Vent Lines Good 1379-D2 Elec. Vent Lines Good 1215-D2 Elec. Vent Lines Good 1349-D2-Elec. Vent Lines Good 1359-D2 Elec. Vent Lines Good Good 381 Rx. Recir. System Low oil in Res.
Added oil 373 Rx. Recir. System Good 388 Rx. Recir. System Good 384 Rx. Recir. System Low oil in Res.
Added oil 390 Rx. Recir. System Low Oil Added oil 415 Rx. Recir. System Low oil Added oil l
413 Rx. Recir. System Low oil Added oil 379 Rx. Recir. System Low oil Added oil 392 Rx. Recir. System Low oil Added oil 378 Rx. Recir. System Low oil Added oil 1088 Rx. Recir. System Good 1015 Rx. Recir. System Good 1016 Rx. Recir. System Good 1004 Rx. Recir. System Good 1010 Rx. Recir. System Good 1005 Rx. Recir. System Good
.
- Elec_tromatic. relief.discharna ninim _ to tha _ Tam _.
~'
2 ENCLOSURE 1 p
Serial #
System Condition Corrective Action 124 Rx. Recire. System Good 140 Rx. Recire. System Good 118 Rx. Recire. System Good 137 Rx. Recire. System Good 86 Rx. Recire. System Good 86 Rx. Recire. Systc; Good 101 Rx. Recire. System Good 136 Rx. Recire. System Good 120 Rx. Recire. System Good 141 Rx. Recire. System Good 383 Rx. Recirc. System Good 389 Rx. Recire. System Good 37S Rx. Recire. System Good 418 Rx. Recire. System Good 391 Rx Recire. System Good 1017 Rx. Recire. System Good 1006 Rx. Recire. System Good 1007 Rx. Recire. System Good g
1014 Rx. Recire. System Good 1012 Rx..Recire. System Good 1011 Rx. Recire. System Good Rx. Recire. System
. Good
+
1008 Rx. Recire. System Good 102S Rx. Recire. System Good 1022 Rx. Recire. System Good 40-SC-47 Core Spray System Good 40-SC-10 Core Spray System Good 1760 Core Spray System Good.
40-SC-8 Core Spray System Good 40-SC-7 Core Spray System Good 2582.
Cdre Spray System Good 40-SC-28 Core Spray System Good 40-SC-27 Core Spray System Good 40-SC-26 Core Spray System Good 40-SC-2S Core Spray System Good 1368 Main Steam Good 1369 Main Steam Good Main Steam Good Main Steam Good 1367 Main Steam Good 1370 Main Steam Good Main Steam Good Main Steam Good 31-SC-6 Feedwater System Good 31-SC-3 Feedwater System Low oil Added oil 1760 Feedwater System Good 31-SC-S Feedwater System Low oil Added oil 31-SC-4 Feedwater System Low oil Added oil-1761 Feedwater System Good 2189 Clean-Up System Good 2370 Clean-Up System Good 2293 Clean-Up System Good 1703 Clean-Up System Good 1789 Clean-Up System Good
/
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ENCLOSURE 1 j
Serial #
System Condition Corrective Action 2167 Clean-Up Discharge Low oil
.Added oil 29-SC-3 Clean-Up Discharge Good 2189 Shutdown Cooling Suct.
Good 2164 Shutdown Cooling Suct.
Good 2190 Shutdown Cooling Disc.
Good 2176 Emerg.Cond. Return Low oil Added oil 2182 Emerg.Cond. Return Good 1219-D2 Emerg.Cond. Return Good 21-27 Emerg.Cond. Return Good 2129 Emerg.Cond. Return Good 2126 Emerg.Co' nd. Return Good 39-SC-IS Emerg.Cond. Return Good 2128 Emerg.Cond. Return Good 2227 High Press Flange Leakoff Good
- 5. Most of the leaks were found at the reservoir end caps.
These were tightened and where necessary teflon tape was used in connections.
In general, there were no inoperable hydraulic shock suppressors.
t e
O my
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