ML17252B062
| ML17252B062 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 05/12/1972 |
| From: | Grier B US Atomic Energy Commission (AEC) |
| To: | Brian Lee Commonwealth Edison Co |
| References | |
| Download: ML17252B062 (2) | |
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UNITED STATES ATOMIC ENERGY COMMISSION DIRECTORAT*E OF REGUIATORY.. OPERATIONS REGION Ill 799 ROOSEVEL. T ROAD GLEN ELLYN, IL.L.INOIS 60137 TELEPHONE (3' 2) 858-2660 Co::::r~onwcalth Edison Company ATI'N:
Hr. Byron Lee, Jr *
. Assistant to the President P.O. Dox 767 Chicago. Illinois 60690 Gcntleraen:
Ma.y 12. 1972 DOcket No. 50*249 Thio re.fora to the inspection conducted by Hcssrs. Dauc:e and Fioi:elli of this office on Hay 4 and S, 1972, of the events associated with the May 4, 1972, Dresden Unit 3 reactor scram and safety valve operation, and to diccussiona of our findings held by Hesars. Dance and Fiorelli l~ith Mevers. Hoyt and Worden of your staff at the conclusion of the inspection.
A:i:'eas ex.-iUlincd dµring tbe ins.pection included equipment responses to the reactor ocram and transicut, reactor operating parameters prior and oubaequcnt to the event, conoequence of li$.,1n etc.nm line safety valve operation on components vithin the drywell, actions taken to correct the failure of the isolation condenser valve to operate c:md pre-startup auCI future tcating programs initiated to determine the cause of safety valve operation at ste3m p;~aa~rc apparently below intended relieving aet points. Within these araas, the 1nspsction co11sisted of selective cY.alllination of procedures and representative records, interviews with plant personnel, and observations by the inspectors.
No itc;ns of noncompliance with.AEC r*ec1uirementa were identified within the scope of thio inspcct~on.
It is our understanding, based on discussions "t-11th your managemti:!nt repreccntativcs, that a prog?"am to dcter:w1c and remedy the cause for the operation of steam line safety valves at *lower than intended relief aetting is being expedited on a prio;-ity basis. We undcratand that the program ~1111 include the following:
- l. Obtaining equipment that ti11l allow test111g of valves witb steam at nominal operating conditions.
- 2. Evaluation of valve des~gn by teoting sa~ety valves in a full scale steam system 1.netallation~
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CoUlUlonwealth Edison Company May 12. 1972
- 3. Installation and use. of appropriate instru'aientation on the main *steam system of one of you** reactor facilities to evaluate systern dynamic conditions and the effect of these conditions on safety valve operation.
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.-.f We will exarrl.ne your efforts in carrying out this program during subsequent inspections.
Should you have any questions concerning this inspection. we will be glad to.discuss them with you.
Sincerely yours, Boyce H. Grier
- Regiona 1 Director cc: w. Worden, Plant Superintendent bee: J. G. Keppler, RO R. H. Engelken, RO A. Giambusso, L P. A. Morris_, RO, RO Files
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