ML20234C318
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UNITED STATES ATOMIC ENERGY COMMISSION 4
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W ASHINGTON. D.C. 20545 j.S I H',*
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March 5, 1973 n,,J e /
-Docket No. 50-265 t !
Mr. Harold G. Mangelsdorf Chairman, Advisory Comittee on Reactor Safeguards U. S. Atomic Energy Commission Washington, D. C.
20545
Dear Mr. Mangelsdorf:
Sixteen (36) copies of the following are transmitted for the Committee's information:
Letter from Commonwealth Edison Company dated February 6, 1973, reporting the leakage of an RHR pump discharge check valve at Quad-Cities Unit 2.
Letter from Commonwealth Edison Company dated February 9, 1973,. reporting the failure of an electromatic relief valve at Quad-Cities Unit 2.
letter from Commonwealth Edison Company dated February 26, i
1973, reporting set point drif ts of switches at Quad-Cities Unit 2.
Sincerely, l
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Donald J.
vholt Assistant Director for Operating Reactors Directorate of Licensing
Enclosures:
As stated Q Q Q W,: 6hfj:=%fiyf
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4D OFFICIAL UgE ONLY Qjtf SWFIDWrr NO.164 CATBOORY B k,%
April 27, k N_ D 7k QuhD CITIEg 2 w
mar b-WR8 H2 EKPIDSION IN OFF-GAS BOLDUP gYSTEM DO MB Licensee letter dated March 16, 1973 provides details regarding March 6, 1973 H2 eEPlosion which Cause: not positively identified; perhaps lightning.
Result:
probably no significant external release of activity.
Release believed to have been within T.S. limits. EgPA filters were damaged.
(Investigation disclosed that filter retainers had not been installed during construction.)
No ACRS action recommended. H e enclosed material may be dis-carded following your review.
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WRS DRIFT OF TRIP POINT gETTINGS OF MSC FIDW dp WITCHES DO MB Licensee letter of March 6,1973 reports finding during routine calibration check that dp switch trip points for two switches had drifted to a setting equivalent to a flow slightly in excess of that required by T.S. for initiation of Group I isolation (1201 i
rat ed flow). Licensee concludes that logic of r6dundant pairs of switches on each steem line would have effected MSLIV closure at 120% flow and that the safety significance of the " drift" was s
minor.
Cause: unknown.
Cure: monitor drift tendency by (routine) surveillance.
No ACRS action recommended. he enclosed material may be discarded following your review.
NAM WRS 1.)
RER PUMP DISCHARGE CRECK VALVE LEAK DO 2.)
MAIN STEAM PRESSURE SWITCH SET POINT DRIFT MB
-1.) Licensee letter February 6, 1973 reports piece of wire discovered, between disc and seat of RER pump check valve. A grinder arber "
was also found in the piping at the check valve location.
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Licensee concludes that reverse flow (leakage) would not have ^ g g
.g been great enough to affect operability of remainder of the R E system.
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Form AEC-318 (Rev. 9-53) AECM 0240 e.r,
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e QED CITIES 2 (continued)
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(during routine calibration) of set point drift (to 4 peig led $..;.k{h f.
2.)
Licensee letters of February 26, 1973 report finding on four MSL pressure switches which are part of the logic of the containment isolation system. Licensee concludes that departure l
from T.S. requirements was insignificant. Error (drift) band j
will be increased and monthly vice quarterly calibrations r111 be made.
No ACRS action recommended. The enclosed material may be discarded following your review.
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RA% urns /mbg QUAD CITIES 2 FILE & CATEGORY B FILE
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Form AEC-518 (Rev. 9-53) AECM 0240 aec us-to--sies-i as-ets
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q QFFICIAL }B3, E SUFF! BENT NO.163 CATEG R Y B Quad Cities 2 b N Ih, 1973
SUBJECT:
IMME IN 0488008 ACTIVI!T @ RATE WR$
DRO NOTIFICATION OF AN INCIDENT M OCCURRENCE, dated March 9,1973 describes short-term (~) hr.) insrease ACRS in stack release rates from 3,000 to 160,000p C1/sec caused by failure of rupture disc is air ejector off-gas holdup system resulting from hydrogen /anygen reaction wh'ich may have been initiated by lightsing strika. No significant personnel esposures resulted and no residual activity was found by a survey of the environs.
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No ACRS action recommended The enclosed material may be discarded following your review.
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Quad Cities 2 file Proj. shelf file ACRS o m cE,
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Form ATC. Sis (Rev. 9-53) AECM 0240 eco
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