ML19338E337
| ML19338E337 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 03/20/1974 |
| From: | Brian Lee COMMONWEALTH EDISON CO. |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| Shared Package | |
| ML19338E336 | List: |
| References | |
| NUDOCS 8009250522 | |
| Download: ML19338E337 (3) | |
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((,G Addr:ss RIply to: Post Othc3 Box 767 Chicago, llhnois 60690 March 20, 1974 Mr. James G. Keppler Regional Director Directorate of Regulatory Operations - Region III U.S. Atomic Energy Commission 799 Roosevelt Road Glen Ellyn, Illinois 60137
Subject:
Response to Letter of James G. Keppler to Byron Lee, Jr., Dated February 28, 1974, Concerning Appa:ent Dresden Unit 1 Violation of AEC Recuirec.ents, AEC.Dkt No. 50-10
Dear Mr. Keppler:
This letter is our response to the subject letter.
The identifying letterc orrespond to the item designations used in R.O.
Inspection Report No. 50-10/74-01, attached to your letter.
A.
The item identified was an open two-inch line (Line No. 5639) penetrating the primary containment.
Leakage through thm.s line was detected on January 25, 1974, during a primary containment leak rate test.
The test was conducted with the reactor in
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shutdown and all fuel removed from the vessel.
Hour by hour calculations indicated that the total leakage from the primary containment was approximately 8.33% per day of sphere free volume.
At the time the leakage through Line 5639 was detected, access to the sphere for investigatory purposes was not possible due to the internal test pressure of 20 psig.
Plant piping drawings indicated Line 5639 to be a capped spare used for future decontamination purposes.
Initial corrective action involved termination of leakage through Line 5639 by installation of a " pancake" in the line.
The installation was made in - flange outside the containment.
Total containment leakage drata ised tc a value less than 0.30% per day following 2 sval~.tlon of the " pancake".
This decrease indicated a lec-.g.:
approximately 8% per day had been passing through Lint SC39.
Following the ccmpletion Of the primary containment leak tert, the sphere war deprecrurized and a ecmplete "irut_ incpecticr O f ' ir.e 5629 V5s mSdf ir.r id e the S p r. C r e.
T-1rrpectiCr dir-CICref th20 thE linE OCrm17.ltC f LT.
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8 0 0 9 250 f2.R
Commonwealth Edison Compa.,
Mr. James G.
Keppler March 20, 1974 2-Further investigation revealed that the chemical cleaning operation performed on "A" reactor water clean up system, which was conducted in August - September, 1968, used Line 5639.
Following the chemical cleaning project, this line was isol.-ted by two air operated valves installed in the line.
The 1..ne was satisfactorily isolated since a successful containment leak test was performed in October, 1969.
Sometime during the period from October, 1969 to the present, the AO valves in the line were removed.
The most probable time of removal was during an extensive equipment removal in the clean up system room con 6 m'ed in 1971; however, no documentation is available indicating these specific AO valves were removed.
Full compliance with Section 4.7.A.l.e of the Technical Specifications was achieved by 2400 hours0.0278 days <br />0.667 hours <br />0.00397 weeks <br />9.132e-4 months <br /> on January 25, 1974 with the installation of the " pancake" described above.
A more permanent termination of Line 5639 was made on March 6, 1974.
At this time the line was cut and capped inside the sphere.
The integrity of the installed cap will be verified by a local leak test.
The present quality assurance program, had it been in effect at the time, would have prevented this occurrence and will serve to prevent this type of occurrence in the future by requiring thorough review of all plant modifications.
In addition, a penetration status procedure will be written and placed in effect prior to unit startup.
This procedure will divide all sphere penetrations into three catecaries.
1.
Penetrations isolated by remotely operated valves.
2.
Spare penetrations isolated by welded caps.
3.
Penetrations isolated by a means other th'an by remotely operated valves or welded caps.
Penetrations in this third category would have their isolation capability explained.
n-Commonwealth Edison Compai.;
Mr. James G. Keppler March 20, 1974 B.
This item involved the failure to report, on a 30 day basis, the fact that the sum of the local leak rate tests exceeded the limit in Section 4.7. A.1.j of the Technical Specifications.
Previous station policy had always been to report the total local leak rate test results within 30 days following the termination of the local test program.
The program was not terminated until January 21, 1974.
The results were reported to the AEC on February 20, 1974.
In order to present a complete picture of leakage testing results, submittal of the report was delayed until all testing was completed.
The valves with excessive leakage were repaired and containment leakage was within limits prior to startup.
In the future, leakage in excess of the Technical Specification limiting conditions for operation will be reported in accordance with Section 6.6.A.2 of the Technical Specifications; i.e.,
24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> telegram and a ten day letter.
In addition to the two apparent violations described above, several understandings between your inspector and the.
station management were listed in the inspection report.
As a
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result of these understandings, the emergency procedures have been revised to require closing the motor operated isolation valves in the primary and secondary feedwater lines after feedwater injection is terminated.
If you have any further questions regarding this matter, please contact this office.
Very truly yours, f
s Byron Lee, Jr.
Vice-President