ML19322E990
| ML19322E990 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 03/14/1980 |
| From: | Crouse R TOLEDO EDISON CO. |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| IEB-80-03, IEB-80-3, NUDOCS 8004040455 | |
| Download: ML19322E990 (3) | |
Text
t 5
March 14, 1980 TUdDU EDISON Docket No. 50-346 RcHAAOP CROUM License No. NPF-3 syjj"*"
mm es9.m Serial No. 1-120 Mr. James G. Keppler Regional Director, Region III Office of Inspection and Enforcement U. S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, Illinois 60137
Dear Mr. Keppler:
This letter is in response to IE Bulletin 80-03 dated February 6, 1980 (Log No. 1-306), as applicable to Davis-Besse Nuclear Power Station Unit No. 1.
Item 1:
Determine if charcoal adsorber cells in use, or proposed for use, have the potential for a loss of charcoal incidental to handling, storage or use (as appropriate).
Particular atten-tion should be directed to examination of a) rivet spacing re-sulting in separation of screen and cell housing and b) adsorber cell or filter housing deformation causing loss of charcoal and/
or channeling. Either of these items could result in a degraded filtration system incapable of performing its intended function.
The preferred method of this determination is a visual inspection of the filter housing and adsorber cells as described in Section 5 of ANSI N510-1975.
If this method is not feasible, state in the report required by Paragraph 4'how the determination was made.
Response: The charcoal adsorber cells installed in the station air filtra-tion systems are welded so that there are no rivets holding the screen and cell housing together. There is a slight settling of the charcoal in each cell but the filter units were tested a I proved operable, with no channeling in the charcoal. The rcoal filter banks were visually inspected by Tolado Edison Nuclear Consulting Services of Columbus, Ohio, be. 'en December 7,
.y79 and December 21, 1979.
The inspection followed t guidelines of e
Section 5 of ANSI N510-1975 and the units were founc acceptable.
MAR 17 1990 THE TOLEDO EDISON COMPANY EDISON PLAZA 300 MADISON AVENUE TOLEDO. OHIO 43652 s co4040t/55
1 Docket No.50-34C License No. NPF-3 Serial No. 1-120 Page 2 Item 2:
For ESF filtration systems, any identified defective cells shall be replaced and the operability of the system (after cell replace-ment) demonstrated by leak testing within 7 days. Preferred method of leak testing is as described in Regulatory Guide 1.52 and Section 12 of ANSI N510-1975.
Response: No cells were found to be defective but the gasket compression on the mounts was found to be insufficient. All cell mounting nuts were tightened to a proper torque setting to obtain the proper gasket compression. A check was initiated for proper torque of the mounting nuts as part of the leak testing procedure.
The filters were leak tested in December 1979 after the mounting bolts were tightened and were demonstrated operable per Regulatory Guide 1.52.
Item 3:
For normal ventilation exhaust filtration systems which employ char-coal adsorber cells and for which radioactive removal efficiency has been assumed in determining compliance with the"as low as reasonably achievable" design criteria of 10 CFR 50, Appendix I, any identified defective cells shall be replaced as soon as possible but at least within 30 days. After replacement, the system should be demonstrated operable by leak testing within an additional 30 days.
Preferred method of testing is as described in Regulatory Guide 1.140 and Section 12 of ANSI N510-1975.
Response: The one normal (Non-Q) exhaust filtration unit with charcoal adcorber cells installed is going to have the charcoal adsorber cells replaced with "Barneby-Cheney Type II FC Type Toploading" adsorbers in early April 1980 with an estimated testing date in the middle of April 1980.
Item 4:
Report in writing within 45 days of the date of this Bulletin the re-sults of the determination required by Paragraph 1.
The report shall include the type of cells employed (manufacturer and cell design),
system containing the cells, observed cell condition (degradation /
sagging) and a discussion of visual inspection procedure and results.
Response
a.
Cell Type - Barneby Cheney Type II FC Toploading - The charcoal adsorbers are welded instead of riveted with no leakage of charcoal b.
Systems - Emergency Ventilation Systems (Q)
Control Room Emergency Ventilation System (Q)
Lab Hood Exhaust System (Non-Q)
O e
Docket No. 50-346 License No. NPF-3 Serial No. 1-120
~
Page 3 c.
Cell Condition - Charcoal adsorber cells were found to be in good condition with slight settling of the charcoal in the cells with no channeling.
d.
Visual Inspection - A visual inspection was made of the systems following the guidelines of Section 5 of ANS1 N510-1975. The filter housing was found to be in good condition along with the adsorber cells.
Yours very truly,
(([ac1_
R. P. Crouse Vice President, Nuclear RPC/TDM/KGM/ daw cc: Director, Division of Fuel Facility & Materials Safety Inspection Office of Inspection and Enforcement USNRC Washington, D. C.
20555