ML19330B359
| ML19330B359 | |
| Person / Time | |
|---|---|
| Site: | Trojan File:Portland General Electric icon.png |
| Issue date: | 06/04/1980 |
| From: | Goodwin C PORTLAND GENERAL ELECTRIC CO. |
| To: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| References | |
| IEB-80-03, IEB-80-3, NUDOCS 8007310472 | |
| Download: ML19330B359 (4) | |
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June 4, 1980 Trojan Nuclear Plant Docket 50-344 License NPF-1 IE Bulletin Response Mr. R. H. Engelken, Director U. S. Nuclear Regulatory Commission Region V Suite 202, Walnut Creek Plaza 1990 N. California Blvd.
Walnut Creek, CA 94596
Dear Sir:
Attached is Portland General Electric Company's response to IE Bulletin 80-03, dated Feburary 6,1980, regarding loss of charcoal from standard Type II, 2-in.
tray adsorber cells.
The inspections required by this Bulletin were performed in accordance with the Bulletin schedule, however, an administrative oversight delayed this response.
Sincerely, sl/
C. Goodwin, Jr.
Assistant Vice President 1
Thermal Plant Operation and Maintenance CG/JWL/MQH/4jed3A27 Attachment c:
Mr. Lynn Frank, Director State of Oregon Department of Energy 8007310N A
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ATTACHMENT 1 Trojan Nuclear Plant Response to IE Bulletin 80-03 INTRODUCTION NRC IE Bulletin 80-03 required all power reactor licensees to inspect 2-in. charcoal tray adsorber cells used in air filtration systems for possible cell deterioration caused by excessive rivet spacing.
The required investigations were conducted and demonstrated that Trojan has no evidence of carbon cell failures, and that the type of carbon cell units used at Trojan are resistant to the type of failure described in IE Bulletin-80-03.
RESPONSE TO ITEMS 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 attention should be directed to examination of a) rivet spacing resulting 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 inspec-tion of the filter housing and adsorber cells as described in Section 5 of ANSI N510-1975.
If this method is not feasible, stata in the report required by Paragraph 4 how the determination was made.
Response
The following is a summary of the 2-in. charcoal tray adsorber cell inspections conducted:
1.
CB-1, Control Room Emergency Ventilation System (ESF)
The CB-1 system consists of two trains (A and B) of HEPA-carbon-REPA filter banks.
Each train utilizes nine 2-in.
tray adsorber cells.
These cells are supplied by the Farr Company, and are a tray-type screened assembly with tack-welded seams.
The tack weld spacings average 1-1/4 to 1-1/2 in. apart on the sides and 1/2 in. to 3/4 in. on the ends. These adsorber banks were visually inspected for evidence of deterioration and inplace leak tested per Trojan Technical Specifications on March 9,1980.
No evi-dence of carbon leakage or depletion and no evidence of physical deterioration of the cell was observed.
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f 1 ATTACHMENT 1 Trojan Nuclear Plant Response to IE Bulletin 80-03 2.
AB-4, Spent Fuel Pool Exhaust System The AB-4 system consists of two trains (A and B) of HEPA-carbon-REPA filter banks.
Each train utilizes 63 2-in.
tray adsorber cells.
These cells are the same as the ones described for CB-1 system above.
ihese adsorber cells were visually inspected for evidence or deterioration and inplace leak tested per Trojan Tech-nical Specifications on March 5,1980.
No evidence of carbon leakage or depletion and no evidence of physical deterioration of the cells was observed.
3.
CS-9, Containment Cleanup Recirculation System The CS-9 system consists of two trains (A and B) of REPA-carbon filter banks.
Each train utilizes 12 2-in. tray adsorber celJs.
These cells are supplied by the Barneby-Chency Company and are a tray-type screen assembly similar to those described for CB-1 and AB-4 systems with tack weld spacings averaging 1-1/4 to 1-1/2 in. apart on the sides and 1/2 to 3/4 in. on the ends. These adsorber banks were visually inspected for evidence of deteriora-tion and inplace leak tested per Trojan Technical Specifi-cations during the week of April 28, 1980. No evidence of carbon leakage or depletion and no evidence of physical deterioration of the cell was observed.
Other charcoal adsorber units at the Trojan plant utilize carbon beds in excess of 2-in. (deep) beds.
These units have also been inspected on a yearly interval and no evidence of tray deterioration or carbon depletion due to leakage has been observed.
Item 2 For ESF filtration systems, any identified defective cells shall be replaced and the operability of this system (af ter cell replacement) demonstrated by leak testing within 7 days.
The preferred method of leak testing is as described in Regulatory Guide 1.52 and Section 12 of ANSI N510-1975.
Response
No defective cells were found.
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ATTACHMENT 1 Trojan Nuclear Plant Response to IE Bulletin 80-03 Item 3 For normal ventilation exhaust filtration systems which employ charcoal adsorber cells and for which radioactive removal efficiency has been assumed in determining compliance with the (as low as reasonably achiev-able) 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 systems should be demonstrated operable by leak -
testing within an additional 30 days.
The preferred method of testing is as described in Regulatory Guide 1.140 and Section 12 of ANSI N510-1975.
Response
No defective cells were found.
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