ML19260C213
| ML19260C213 | |
| Person / Time | |
|---|---|
| Site: | Pilgrim, 05000471 |
| Issue date: | 10/29/1979 |
| From: | Andognini G BOSTON EDISON CO. |
| To: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| IEB-78-10, NUDOCS 7912260065 | |
| Download: ML19260C213 (2) | |
Text
,e".
....~
g BOSTON EDISON COMPANY GENERAL orrtCEs 800 80VLSTON STREET SOSTON, M ASEACNUSETTm 0219 9 G. Camb ANOCSNING SUPERINTENDENT NUCLEAR OPENATIONS DEPARTMENT October 29, 1979 BEco. Ltr. #79-211 Mr. Boyce H. Grier, Director Office of Inspection and Enforcement Region I U.S. Nuclear Regulatory Commission 631 Park Avenue King of Prussia, PA.
19406 License No. DPR-35 Docket No. 50-293 Additional Information on Bergen-Patterson Hydraulic Shock Suppressor Accumulator
, Spring Coils (IE Bulletin #78-10)
Dear Sir:
In a letter dated September 13, 1979, you etated that adcitional information is needed to complete your review of our response to IE B tlletin #78-10 (Bergen-Patterson Hydraulic Shock Suppressor Accumulator Sord ag Coils).
Our responses to your specific questions are provided below.
1.
What actions will be initiated if subsequent testing and/or inspection identifies continued or accelerated corrosion of accumulator springs?
Response
All safety-related hydraulic snubbers were visually inspected during 1979 as required by PNPS Technical Specification 4.6.I.1.
Approximately 30 snuubers were inspected and no broken or severely corroded springs were observed.
The springs were replaced with original equipment because of the unavailability of replacement parts.
It is the Boston Edison Company's position that Technical Specification 4.6.I.1 requirements are sufficient to ensure adequate operability levels are maintained. Technical Specification 4.6.I.3 requires functional testing of 10 hydraulic snubbers or 10% whichever is less each refueling cycle. We have ordered replacement parts and presently plan to replace springs in those hydraulic snubbers functionally tested each outage.
1616 054 7912 60 2
3 BOSTON EDISON COMPANY Mr. Boyce H. Grier, Director October 29, 1979 Page 2 2.
What surveillance testing outside of refueling outage functional testing is likely to detect accumulator spring failure due to corrosion?
Response
There are no surveillance tests outside of refueling outage functional testing which will detect accumulator spring failure due to corrosion.
3.
What ef feet would a failed accumulator spring have on operability of snubbers?
Response
The unit remains functional even with a broken spring; hiewever, the possibility does exist that the debris from a broken spring coil could in fact cause damage to the Accumulator Piston U-Cup Seal resulting in possible leakage of fluid. The remote possibility for the Accumulator Piston to become jammed in the tube also exists; however, this has not been experienced.
4.
What ef fect would corrosion products in hydraulic fluid ha're upon opera-bility of snubbers?
Response
Corrosion products from accumulator springs have no effect on the hydraul;.c fluid since the spring is on the dry side of the U-Cup Seal.
We trust that the information provided is responsive to your request. However, if you have any further questions, please contact us.
Very truly yours, d
on 1616 055