ML20037B522
| ML20037B522 | |
| Person / Time | |
|---|---|
| Site: | Dresden, Quad Cities  |
| Issue date: | 09/14/1974 |
| From: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Brian Lee COMMONWEALTH EDISON CO. |
| References | |
| NUDOCS 8010140643 | |
| Download: ML20037B522 (1) | |
Text
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I UNITED STATES p
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ATOMIC ENERGY COMMISSION y, j y
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DIRECTORATE OF REGULATORY OPERATIONS
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REGION lli 799 ROCSEVELT RO AD mg GLEN ELLYN, ILLINOIS '60137 (312) 454-2060 PSEo 1 S 1974
-i.h u44 - cw neek t me..w alo AT25: Mr. Dyrea Ime, Jir.
Donket Me. 50-257 Ties Puesideas Bookst Es. 5& 249 F. O. Boa 747 Doekaa Es.56-254 Chiange, 1111 asia 60690 Bookst Es.56-265 Semelms The== eta==d 30 htia*4= regensta assimme by yee with n oord to your besling ustar vuester (B E) fasilities with operating liameses.
shseld one or uste of year BIE fam4 titian act ma=*mia the bypeso piping system doesribed in this Bellatia. as astian is - 9 en your part. A writtaa reopease to this offise is n;_ M witkia 10 days, hooever if you de*===4== this Bellatia met to be applisabia to year EIR familities.
Should yes have ;
T* n regarding this Bellatim er actions regnested of you, plasse emanast this offias, a4===cely, Jesse G. Espplar Marianal Director i
o Realeomre:
30 httamin 74 40 bec: g Cantral Files 30 Filaa FDR Local PDR 80204o(9'3 p
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s September 19, 1974
, DRO Bulletin No. 74-10 1
1 FAILURES IN 4-INCH 3YPASS PIPING AT DRESDEN 2 The Commonwealth Edison Company notified the Region III Office of the Directorate of Regulatory Operations by telephone on September 13-15, 1974, of the finding of through-wall cracks in each of two 4-inch dia-meter bypass loops around the discharEe valves of the recirculation pumps at the Dresden 2 facility.
Early warning of reactor coolant leak-age was provided by the plant's dryvell sump collection system.
In each instance the cracks were in the heat affected zone of stsialess steel welds joining the 4-inch piping to weld-o-lets on the 28-inch dia=eter main coolant recirculation piping. The cracks were circunfer-ential, from 3/4-inch to 3-inches in length on the OD and extending to substantially greater lengths on the ID of the pipes.
In one instance (the "B" loop bypass line), the area containing the
' crack can be isolated for repair utilizing valves pres ntly in e
stalled.
In the other instance (the "A" loop bypass line), the area containing the crack cannot be isolated from the reactor pressure vessel with existing valves in the piping syste=.
Procedures for the repair of this portion of the piping system are presently being consid-ered by the licensee.
Metallurgical a m inations are being conducted by the licensee's consul-tants to aid in determining the cause and mechanism of failure.
Several days may be required for such determination.
Inspections conducted by the Cos:=onwealth Edison Co=pany at their Quad Cities Unit 2 on September 15, 1974, have revealed a crack in similar piping at that facility.
Action Recuested of Licensees 1.-
For those boiling water reactor (BWR) facilities presently shutdown, ara ~ine (by ultrasonic or other suitable volumetric nondestructive evnination technique) all accessible welds in the bypass piping lines around the recirculation valves for evidence of crack indica-tions similar to those discussed above. Your written reply to this Bulletin should discuss those welds determined to be inaccessible for er mination.
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g R0 Bulletin No. 74-10 Sepcesber 19, 1974 2.
For those BWR facilities presently operating, conduct the ei.imina-tions discussed in 1., above, at the earliest of the following conditions:
a.
Next scheduled shutdown b.
Such time that (within the sensitivity specified in paragraph C.S. of Regulatory C 'de 1.45) any reactor coolant leakage detection systen 1_eates, within a period of four hours or less, either an increase in unidentified leakage to twice the determined normal rate of unidentified lea'kage or an increase in the rate of unidentified leakage by two (2) gpm or more.
(In no case, however, shall the rate of leakage exceed that specified by the Technical Specifications without those actions required of the Technical Specifications being taken.)
Sixty (60) days from the date of this Bulletin.
c.
3.
Notify this office by telephone within 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> and in writing within 10 days of the =easures you have implemented, or plan to i=plement, with regard to those actions requested in 1. and/or 2., above.
4.
Notify this office by telephone within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> (with written confir=ation within 10 days) of the results of examinations conducted in response to this Bulletin. A copy of the written notification of ernmination results (including all attachments) should be sent to the Assistant Director for Construction and Operations, Directorate of Regulatory Cperations, AEC 5: Jquarters in Washington, D. C.
Actions Requested of Licensees Mav be Modified The actions requested of licensees, above, may be modified by this office as meaningful results are available from the metallurgical examinations and failure analyses presently in progress.
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