ML20090D360
| ML20090D360 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 12/05/1973 |
| From: | Schneider R NIAGARA MOHAWK POWER CORP. |
| To: | Skovholt D US ATOMIC ENERGY COMMISSION (AEC) |
| Shared Package | |
| ML20090D351 | List: |
| References | |
| 8783, NUDOCS 8302280028 | |
| Download: ML20090D360 (3) | |
Text
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O NIAGARA MOH AWK POWER CORPORATION I
NIAGARA MOHAWK 300 ERIE BOULEVARD WEST
,., $ .! 2.: [N.,
SYR ACU S E, N. Y. 832 02
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Mr. Donald J. Skovholt C.
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Assistant Director for Reactor Operations h.
8 ' "Y Division of Reactor Licensing United States Atomic Energy Commission
- fh Washington, D. C.
20545 Re:
Provisional Operating License:
DPR-17 Docket No.: 50-220
Dear Mr. Skovholt:
This letter references yours of October 1, 1973 in which you requested a scheduled inspection of the accessibic Bergen-Paterson snubbers every 30 days. The program you have requested has been implemented and is being per-formed by the Plant Maintenance Department. Although certain misunderstandings about the frequency of inspection was incurred initially this has been rectified as follows:
1.
All Bergen-Paterson snubbers will be inspected once each 30 days.
If defects are found they will be reported in accordance a.
with Section 6.3 Technical Specifications.
b.
A written report will be furnished within 15 days after the inspection if all snubber.s are satisfactory.
2.
The inspection will cover:
a.
Condition of seals determination - a visual inspection of each hydraulic shock absorber will be performed.
Signs of leakage will indicate degradation of the seals, b.
The overall integrity of the shock absorber assembly will be verified by visual inspection.
3.
Written surveillance procedures will be implemented and a check-off sheet used to record condition of each snubber. These will be filled and availabic for review. to this report denotes the serial number of the snubbers that will be inspected as well as their location.
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- 2 Mr. Donald J. Skovholt December 5, 1973 U.S. Atomic Energy Commission The snubbers have been inspected twice in the 40 days since my October 26, 1973 submittal concerning the Drywell snubber inspections.
In both cases no deterioration of seals or other degradation of the assembly was noted.
The inspection dates were October 30, 1973 and December 4, 1973.
The next scheduled inspection is on January 2,1974.
Very truly yours, Original Signed by - R. R. Schneider Rudolph R. Schneider Vice President - Electric Operations RRS:cm Enclosure cc: James P. O'Reilly RO:1 4
3 g ENCLOSURE 'l t
. BERGEN-PATERSON'" SNUBBERS" MdfliL NO.
SERIAL NO.
LOCATION SYSTEI Emergency Cooling System HSSA - 30 F 84806-3 A
~340' Steam Supply 30 F 84806-3 B 340' Steam Supply Emergency Cooling System HSSA - ~30 F 84806-3 C-340' Steam Supply Emergency. Cooling System HSSA -
Emergency Cooling System HSSA - 36 ~
F 84806-3 D 340' Steam Supply Emergency Cooling System HSSA - 30 F 84806-3 E 340' Steam Supply Emergency Cooling System-HSSA - 30 F 84806-3 F 340' Steam Supply Emergency Cooling System IISSA - 30 F 84806-3 G 340' Steam Supply Emergency Cooling System HSSA - 30 F 84806 3 H 340' Steam Supply Emergency Cooling System HSSA - 30 F 84806-3 I 336' Steam Supply Emergency Cooling System HSSA - 30 F 84806-3 J 336' Steam Supply 1
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l NIAGARA MOHAWK POWER CORPORATION NIAGARA MOHAWK 3oo ERIE DouLEVARD WEST SYRACU$C, N Y 83202 i
October 26, 1973
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Ffr. Donald J. Skovholt Ih p
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Assistant Director for Reactor Operations Division of Reactor Licensing Y
[lQy b73 % *h Unit 6d State's Atomic Energy Commission
' S-Washington, D. C.
20545 gi:#
l Re: Provisional Opefating Licem e: DPR-17 N
Docket No.:
50-220 4
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Dear Fir. Skovholt:
On October 18, 1973, the Nine b!ile Point Unit #1 reactor was shut down, the result of an increasing rate of unidentifiable leakage in the drywell.
l The shutdo m, which occurred during the routine R0:I AEC Inspection, provided the opportunity to. perform the following:
l 1.
Shutdown b!argin Demonstrations - in acco'rdance with your letter l dated September 25, 1973.
2.
Inspections of hydraulic shock suppressors in response to your request on ' October 1,19732 and R0:I telephoned request 3 on Ju!y 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 ycur letter of 5
September 28,~1973,
On August 17, 1973 leakage into the Drywell Floor Drain Tank (DNFDT) had increased to 2.5 gpm.
Reactor Recirculation Pump 12 (RRP 12) was the immediate suspect as equalization was occurring between the low and high pressure seal.
Once RRP 12 was secured the DNFDT Icakage decreased to less than.25 gpm.
On October 1, 1973, with RRP 12 still secure leakage again was gradually increasing to the DNFDT.
With leakage approaching 2.8 gpm on October 6, 1973 Station Supervision ordered increased surveillance on the DNFDT Icakage.
Although Technical Specifications call for a check of Icakage only once per day, it was deemed necessary to continually plot leakage cach hour to note trends or other Indications which could provide an insight into the source of leakage.
The Radiation Protection and Chemistry section had already~
determined tipt the tiajor percentage of leaking liquid was not reactor coolcnt.
On October 18, 1973 with DNFDT leakage indicating approximately 4.5 gpm, Plant Supervibion ordered the reactor shutdown.
During the subsequent drywell inspec-l tion the source of leckage was identified as steam Icaks thru the valve packing on'two cicctromatic relief systems blocking valves and a small leak on RRP
Wr. Donald J. E~Jvholt October 26, 1973 U.S. Atomic Energy maission j
During the shutdown and at Xenon 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 mado during the shutdown. 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 wcre found to be void of fluid.
A certain amount of Icakage 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 pressuri:cd to 35 psig and the decay in pressure noted over one half hour. No loss of' pressure was observed.
Very truly yours, S dolph R. Schn/eid[r o
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-O'Reilly Oct. 10, 1973 5.' Ltr. Skovholt - Schneider Sept. 28, 1973 O
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ENCLOSURE 1, liYDRAULIC SHOCK SUPPRESSOR l
l 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- 02 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 1450- 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-D7 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 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. Rc"!
System Good 1015 Rx. Recit, System Good 1016 Rx. Recir. System Good 1004 Rx, Recir. System Good 1010 Rx. Recir. System Good 1005 Rx. Recir. System Good
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- E1cetromatic r l'
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Scrial #
System Condition Corrective Action 124 Rx. Recire. System Good 140 Rx. Reci,rc. System Good 118 Rx. Recire. System Good 137 Rx. Recire. System Good 86 Rx. Recire. System Good 86 Rx. Recire. System Good 101 Rx. Recire. System Good 136 Rx. Recire. System Good 120 Rx. Recire. System Good 141 Rx. Recire. System Good 383 Rx. Recire. System
. Good 389 Rx. Recire. System Good 375 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, fy ".cm Good 1014 Rx. Recire. System Good 1012 Rx. Recire. System Good 1011 Rx. Recire. System Good Rx. Recire. System
. Good 1008 Rx. Recire. System Good 1025 Rx. Recire. System Good 1022 Rx. Recire. System Good 40-SC-47 Core Spray System Good j
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.
C6re 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-25 Core Spray System Good 1368 blain Steam Good 1369 Flain Steam Good
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b!ain Steam Good blain Steam Good 1367 b!ain Steam Good 1370 b!ain Steam Good blain Steam Good blain Steam Good 31-SC-6 Feedwater System Good 31-SC-3 Fecdwater System Low oil Added oil 1760 Feedwater System Good 31-SC-5 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.R eturn 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.Cond. Return Good 39-SC-IS
.Emerg.Cond. Return Good 2128 Emerg.Cond. Return Good 2227 High Press Flange Leakoff Good S. Most of the leaks were found at the reservoir end c~aps.
These were tightened and where necessary teflon tape was used in connections.
In general, there were no inoperabic hydraulic shock suppressors.
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