ML20084L135
| ML20084L135 | |
| Person / Time | |
|---|---|
| Site: | Quad Cities  |
| Issue date: | 04/29/1974 |
| From: | Kalivianakis N COMMONWEALTH EDISON CO. |
| To: | Oleary J US ATOMIC ENERGY COMMISSION (AEC) |
| Shared Package | |
| ML20084L137 | List: |
| References | |
| NJK-74-49, NUDOCS 8305200277 | |
| Download: ML20084L135 (2) | |
Text
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4 C 's Outd Cita 2nerating Station
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Telephone 309/654-2241 (P
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50-254 3
h 1, April 29,1974 9;
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Mr. John F. O' Leary, Director Directorate of Licensing
- /. / '
t Regulation
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U. S. Atomic Energy Co:r:nission Washington, D. C.
20545
Reference:
Quad-Citics !!uclear Power Station Unit 1, Docket 1 o. 5
~ 4, DPR-29, Appendix A, Sections 1.A.2, 3.2.A., Table 3.2.1.
and 6.6.B.l.a.
Dear Mr. O' Leary,
The purpose of this letter is to inform you of the details concerning the HPCI arra h1 h tc perature isolation terperature switchcs, which were 5
found with setpoints excceding the Technical Specifications Limiting Conditions for Operations, given in table 3.2.1.
This abnormal occurrence was reported to you by telegram, and to Region III, Directorate of Regu-L latory Operations by telephone a rrd telegram, on April 20, 1974 PROBLE!! A?3 II.VESTICATIO:
On April 19, 1974, with unit one in the cold shutdown mode for refueling, routinc surveillance was perforscd on the HPCI area high terpcrature iso-1 lation temperature switches and nine of the sixteen trippcd at values f
execcding the Limiting Condition for Operationof$200 F.
The "as found" setpoints are as follows:
EQUIF?:EUT PIECE IlWrERS SETPOIICS, F
'IS-1-23 70 A 208 B
202 TS-1-2371 A 206 C
2 03 TS-1-2372 A 209 D
230 TS-1-2373 P 202 g
C 205 5
D 202 i)
These switches were recalibrated to trip at 185 F+5 F, - 10 F.
!j M
DETERI'II!ATIOI: OF CAU3E L:3 CO?FECTPjE ACTICI!
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it The switches were originally calibrated to trip at 200 F.
Normal instru-i ment drift caused the sctroints to execcd the limiting condition for oper-
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ation, but they have since been recalibrated to 15 F below the limit to allow for this drift.
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Mr. J. F. O' Lea ()
g April 29,1974 SAFETY I?SLICATIO!!S The basis for Section 3.2 of the Technical Specifications states that a setroint of 200* F will enable leaks of 5 to 10 G.P.K. to be detected.
Because not all the switches had drifted, the isolation would still have occurred at 200* F.
Iowering the setpoints 15' F makes smaller leaks detectable and therefore involves no safety implications.
CUMUIATIVE EXPERIEt:CE This occurrence represents the first recalibration of the HPCI area high temperature isolation switches at Quad Citics Station.
tive experiene.c data is available.
No cumula-Very truly yours, CGT.0?MEALTH EDISON CO:PA!IY QUAD-CITIES IJUCLEAR POER STATIO:1 n
/[-l$f XhhI'Yb-H. J. Kalivianakis Station Superintendent NJK/ REQ /caa j
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