ML20004F083
| ML20004F083 | |
| Person / Time | |
|---|---|
| Site: | Dresden, Zion  |
| Issue date: | 06/09/1981 |
| From: | Swartz E COMMONWEALTH EDISON CO. |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| IEB-81-01, IEB-81-1, NUDOCS 8106160481 | |
| Download: ML20004F083 (6) | |
Text
~
A Commonwealth Edison
,/ - One First National Pfara, Chicago. filinois i O jy Address Repty to: Post Office Box 767 (y/ Chicago Illinois 60690 , gcu s\\ S% h 'g $ g) June 9, 1981 k/ Q Mr. James G. Keppler, Director Directorate of Inspection and Enforcement - Region III U.S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, IL 60137
Subject:
Drescen Station Unit 2 Zion Station Unit 1 Response to IE Bulletin 81-01. Rev. 1, " Surveillance of Mechanical Snubber:". Item #4 Regarding Results of the Inspections Performed NRC Docket Nos. 50-237 and 50-295 Reference (a): J. G. Keppler letter to C. Reed dated March 4, 1981. (b): T. J. Rausch let'ter to J. G. Keppler dated March 27, 1981.
Dear Mr. Keppler:
In response to the Item 4 requirements of the Bulletin, enclosed I please find the results of the inspections performed for Dresden Unit 2 ana Zion Unit 1. Refer to the Reference (b) letter for our inspection program schedules for the remaining units. To the best of my knowledge and belief, the statements contained herein are true and correct. In some respects these statements are not based on my personal knowledge but upon information furnished by other Commonwealth Edison Employees. Such information has been reviewed in accordance with Company practice and I believe it to be reliable. T6// .s /// l h JUN 121981 81061 e oyg,
~ J. G. Keppler June 9, 1981 Please address any questions you may have concerning this matter to this office.
- Very truly yours,
,c-E. Douglas Swartz Nuclear Licensing Administrator Enclosure cc: Director, NRC Office of Inspection and Enforcement Region III Inspector.- Dresden Region III Inspector - Zion im .i SUSSCRIBED ano SWORN.to before me.this 9#h day of C4<46 1981 ^ j w th 8-zM , Notary Public l 'e l 2141N i l 1 i
ENCLOSURE Commonwealth Edison Response to I.E. Bulletin 81-01, Item #4 Dresden Unit 2 Dresden Station has performed the visual examination and functional test of the mechanical snubbers installed or planned to be installed on safety related systems on Unit 2 &nd on 3 safety related snubbers removed from Unit 3. There were not any snubbers found during the visual examinations to be of questionable operability, and the functional testing required verified that all of the snubbers were operable. The visual examination for previously installed snubbers was conducted in the following manner. The inspection consisted of a check on the cold piston setting indicating abnormal pipe movement, an investigation for possible visible damage of the snubber and its attachments indicating an inoperable snubber, and an inspection of the structural attachments and piping for visible damage due to snubber failure. The visual examination of mechanical snubbers to be installed under plant modifications consisted or inspection of snubber and attachments and structural attachments for possible damage caused during shipping, assembly and installation.. This ensured that the snubber integrity was maintained prior to and after installation. l The functional test consisted of a verificiation of freedom of movement by taking the snubber and applying sufficient force to fully stroke the snubber in both compression and tension modes. The . snubbers were not allowed to bottom out, thus preventing possible damage to the internals and ensuring that snubber integrity was maintained during the test. j During the Unit 2 January, 1981, refueling outage, the 10 Pacific Scientific mechanical snubbers previously installed were visually inspected, removed, and functionally tested. Prior to installation, the 45 Pacific Scientific mechanical snubbers to be I installed in the drywell, as a result of modifications to the plant, were visibly inspectea and functionally tested as described above. In addition, the snubbers were inspected after installation as part of the ISI program and snubber program to ensure that no damage oCCurreu. On Apri) 4, 1981, Unit 3 was shutdown for a weekend outage to return the Hiih Pressure Coolant Injection System (HPCI) to t operability. As a result of the engineering evaluations done on the Unit 3 HPCI System due to I.E. Bulletin 79-14, 3 snubbers were l removed. The visual inspection and functional test were performed, verifying snubber operability. Tne remaining snubbers will be inspected and tested during the Unit 3 January, 1982, refueling outage as previously reported.
2-The results of the visual inspection and functional test determined that all 58 snubbers were operational as required by I.E. Bulletin 81-01. The attached table supplies the number of snubbers inspected, their manufactureb, moael number, and size as required by Item 4b. In addition, the snubber status at the time of the functional test is' supplied on the attached table. e l l l l l _ _. ~... _. _..-..
ATTACllMENT Manufacturer Model No. Size Number Status at Time of Functional Test Pacific Scientific Co. PSA-10 15 Kips 3 Unit 3: removed from drywell per IEB 79-14 Pacific Scientific Co. PSA-35 50 Kips 3 Unit 2: prior to installation in a drywell for IEB 79-14 1 Pacific Scientific Co. PSA-35 50 Kips 16 Unit 2: prior to installation for rep 1. cement of the drywell li hydraulic snubbers with mechanical snubbers modifi-cation Pacific Scientific Co. PSA-10 15 Kips 10 Unit 2: removed from drywell per IEB 79-14 Pacific Scientific Co. PSA-10 15 Kips 4 Unit 2: prior to installation for i l replacement of the drywell hydraulic snubbers stith mechanical snubbero modifi-cation 1 Pacific Scientific Co. PSA-10 13 Kip.s 19 Unit 2: prior'to installation in l drywell for SRV modification i Pacific Scientific Co. PSA-3 6 Kips 3 Unit 2: prior to installation in 4 drywell for IEB 79-14 I i i i i i
Zion Unit 1 All Unit I safety-related mechanical snubbers which are installeo or are ready to be installed have been visually inspected and exercised manually according to the requirements of the subject bulletin (Action Item la). Results of this inspection indicate that all Unit 1 safety-relateo mechanical snubbers were undamaged and were able to be stroked satisfactorily. A total of 29 mechanical snubbers were visually inspected and manually 'strokeo as follows: Mechanical Snubbers Installed: Quantity Manufacturer Model No. Stroke (in) 6 Pacific Scientific PSA-1 4 7 Pacific Scientific PSA-3 5 4 Pacific Scientific PSA-10 6 6 Pacific Scientific PSA-35 6 Ready to be Installed: Quantity Manufacturer Model No. Stroke (i i 1 Pacific Scientific PSA-1/2 2.5 1 Pacific Scientific PSA-3 5 2 Pacific Scientific PSA 6 i 2 Pacific Scientific PSA-35 6 All Unit 1 safety-related mechanical snubbers are consioered operable ano no further corrective action is deemed necessary, t l i I 1 1 ., _ _ _}}