ML20234D359
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- W ASHINGTON, D.C. 20545 May 18, 1972 j
36 Docket:Nos.'50-254 and 50-265 hkf Lun4TTEfhf'
- a. arrcom5 Dr. Chester P. Siess Chairman; Advisory Committee j
on Reactor Safeguards U. S. Atomic Energy Commission Washington, D. C.
20545
Dear Dr. Siess:
Sixteen (16) copies of the following are transmitted for the i
Co:rnittee's information:
j Letter from Commonwealth Edison Company dated May 4, 1972, reporting an operating error on Quad-Cities ucit 2 that 3
affected the Unit 1 emergency systems.
_ g, Letter from Commonwealth Edison Company dated May 9,1972, I
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requesting use of respiratory protective equipment in
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5 determining whether individuals in restricted areas at. the (y K i 0
/ Quad-cities reactors are exposed to concentrations of air-
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borne radioactive material in excess of specified limits.
Sincerely,
, je ff,//hy Yh Donald J. Skovholt O
^ '/R 't p I$h,EI Assistant Director hy for Beactor Operations (f. k.
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i-i Division of Reactor Licensing l
Enclosures:
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G 7ICIAL USE Op1,Y SUFFLEENT No.153 CATEGORY B 89:Ci f '
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Quad Citles 1 and 2 May 26,1972 HMH & ACRS Operator Error Affecting Protection System By letter dated May 4,1972, Cosanonwealth Edison reported an incident which occurred during startup testing of Unit 2, affected the Unit 1 protection system and may have revealed a design error in the diesel-generator excitation circuitry.
The water level in Unit 2 was to be lowered for a final visual inspection before putting the vessel head in place and the use of jumpers was authorised to prevent automatic startup of the Unit 2 emergency system. The jumpers were installed on the Unit 1 system in error, effectively elimi-nating the Unit 1 ECCS, etc., for about 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br />. As a re-suit the No. 2 and No. 1/2 generators were started automatic-ally when the water level was dropped but the No. 2 generator became unstable and was removed from service after about 35 minutes. The cause of failure was shorting of six selenium rectifiers installed for are protection across the silicon dime rectifiers in the excitation section of the No. -2 generator. The silicon rectifiers have been replaced and the manufacturer is studying the design to decide on possible final corrective action.
The improper jumper placement was made after the required 2 independent checks, etc., and CE 's corrarctive actions (e.g.,
inform all shif t personnel, review by Safety Comunittee, add a third independent check, add equipment labeling, discuss testing sensor circuits after jumper placement) apparently reflect their feeling that, while the incident can not be ignored, it is also not possible absolutely to preclude similar errors.
& l{ N W b/ N The Regulatory Staff is currently considering the matter g'g f gg { //0/4 of more distinctive labeling as a means of assuring that
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analogous systems are not confused at multi-unit plants.
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No ACRS action is recocumended.
The enclosed material may be discarded after your review.
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. 5.l26.l12, Form AEC-518 (Rev,9-53) AECM 0240
- v. s. oovEnwutNT PRDfTDiG OFFICE : 1970 0 - 406 846 4
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y SUPPLEMENT NO.153 CATEGORY B Quad Cities IDel Tech spec Channe May 26, 1972 By letter dated May 9,1972, Commonwealth Edison requested a change which would allow the use of protective equipment in determining individual exposures of plant personnel.
No ACRS action is recommended.
The enclosed material may be discarded af ter your review.
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FILE: Quad Cities Project & Cat B Files i
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.r Form AIC-318 (Rev. 9-53) AECM 0240 U. S, OOVERNMENT PRDITING OFFICE r 1990 J 346 i