ML19329E402
| ML19329E402 | |
| Person / Time | |
|---|---|
| Site: | Dresden, Midland  |
| Issue date: | 10/09/1974 |
| From: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Howell S CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| References | |
| NUDOCS 8006120726 | |
| Download: ML19329E402 (1) | |
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DIRECTORATE OF REGULATORY CPERADONS o
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REGION lli FIS O 799 ROOSEVELT ROAD mmg GLEN ELLYN. ILLINOIS 60137 (312) 85s-2660 October 9, 1974 Consumers Feuer Company Docket No. 50-329 ATTN Ifr. Stephen H. Howell Docket No. 50-330 Vice President 1945 West Parnall Road Jackson, Michigan 49201 Gent 1 amen:
Enclosed is 20 h11stin 74-10 which is forwarded for your information.
No action is requested of you in response to this Bulletin.
Should you have questions regarding this Bulletin, please contact this office.
Sincerely, James G. Kapplar Regional Director
Enclosure:
uMS DOCOMENT CONT RD Bulletin 74-10 1
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September 19, 1974 DRO Bulletin No. 74-10 i
FAILURES IN 4-INCH BYPASS 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-mater bypass loops around the discharge valves of the recirculation pumpo at the Dresden 2 facility. Early warning of reactor coolant leak-age was provided by the plant's drywell sump collection. system.
In each instance the cracks were in the heat affected zone of stainless steel welds joining the 4-inch piping to weld-o-lets on the 28-inch diameter main coolant recirculation piping. The cracks were circumfer-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 presently in-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 system. Procedures for the repair of this portion of the piping system are presently being consid-ered by the licensee.,
Metallurgical examinations 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 Commonwealth Edison Company at their Quad Cities Unit 2 on September 15, 1974, have revealed a crack in similar piping at that facility.
Action Requested of Licenseas
- 1. -
For those boiling water reactor (BWR) facilities presently shutdown, av=mine (by ultrasonic or other suitable volumetric nondestructive examination 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 examination.
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RD Bulletin No. 74-10 September 19, 1974.
2.
For those BWR facilities presently operating, conduct the examina-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 Guide 1.45) any reactor coolant leakage detection system indicates, within a period of four hours or less, either an increase in unidentified leakage to twice the determined normal rate of unidentified leakage 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.)
c.
Sixty (60) ' days from the date of this Bulletin.
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 measures you have imple.mented, or plan to implement, 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 confirmation within 10 days) of the results of examinations conducted in response to this Bulletin. A copy of the written notification of examination results (including all attachments) should be sent to the Assistant Director for Construction and Operations, Directorate of Regulatory Operatione, AEC Headquarters in Washington, D. C.
Actions Requested of Licensees May 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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