ML19309D330
| ML19309D330 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 03/18/1980 |
| From: | Daltroff S PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| To: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| IEB-80-03, IEB-80-3, NUDOCS 8004100261 | |
| Download: ML19309D330 (3) | |
Text
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PHILADELPHIA ELECTRIC COMPANY 23O1 M ARKET STREET P.O. BOX 8699 PHILADELPHI A, PA.19101 G'M""#
swirtos t. oALTaore ELacfmCPa c lose March 18, 1980 IE Bulletin 80-03 Mr. Boyce ti. Grier, Director Office of Inspection & Enforcement Region I US Nuclear Regulatory Commission 631 Park Avenue King of Prussia, PA 19406
Dear Mr. Grier:
This is in response to your letter of February 6,
- 1980, which forwarded IE Bulletin 80-03.
The problem with rivet spacing identified in your letter is not applicable to Peach Bottom Atomic Power Station (PBAPS), however, the required inspection was performed to determine if any other problems could result in a degraded filtration system.
The actions requested and our responses are listed sequentially below.
Actions to Be Taken by Licensees 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 inspection of the filter housing and adsorber cells as described in Section 5 of ANSI N510-1975.
8004100
r L
Mr. Boyce H.
Crier Page 2 Resgonse Based on a visual inspection of the charcoal adsorber cells in use or proposed for use at PBAPS, there are no cells which have the potential for loss of charcoal incidental to handling and storage.
The problem with rivet spacing identified in your letter is not applicable to PBAPS since the screen and cell housings are tack welded at approximately 1 1/2 inch intervals.
The visual inspection of the filter housing and the charcoal adsorber cells was performed in accordance with Section 5 of ANSI N510-1975.
There was no separation of the screens from the housing, no sagging of the adsorber cells or filter housings and no degradation of componen'ts other than the item identified below.
A potential problem has been identified with respect to the charcoal adsorber cells presently in use.
The rivets which hold the charcoal fill port covers in place on the front of the adsorber cells are rusting.
These rivets were supplied by American Air Filter Company and do not meet the specifications originally defined by Bechtel Corporation.
All charcoal adsorber cells in the Standby Gas Treatment System (SBGTS), the Control Room emergency ventilation system, the off gas recombiner system, and in storage at Peach Bottom presently use these rivets.
Inspection of the filters in all of these systems has shown no instances of failure of these rivets such that the port covers fall off during operation.
In addition, an analysis of the effect of losing a port cover indicates that the efficiency of the charcoal adsorber cell would not be decreased below allowable limits.
All rivets presently installed in adsorber cells in the SBGTS and the Control Room emergency ventilation system will be replaced with stainless steel rivets by March 31, 1980.
The rivets in the charcoal adsorber cells in storage will be replaced before they are installed in any ventilation systems.
2.
For ESF filtration systems, any identified defective cells shall be replaced and the operability of the system (after cell replacement) 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
There were no cells replaced in' Engineered Safety Feature (ESF) filtration systems (SBGTS and Control Room emergency ventilation system), as a result of this inspection.
However, it will be necessary to remove the charcoal adsorber cells to replace the rivets as indicated in item 1.
After replacement of the rivets, the operability of each system will be demonstrated by leak testing within seven days.
Mr. Boyce H.
Crier Page 3 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 achievable" design criteria of 10 CFR 50, Appendix I,
any identified de f ec t ive 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
There were no off gas recombiner adsorber cells replaced as a result of this inspection, however, it will be necessary to remove the charcoal adsorber cells to replace the rivets as indicated in item 1.
The operability of the system will be demonstrated by leak testing after the rivets have been replaced.
Very truly yours, I
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US Nuclear Regulatory Commission Office or Inspection & En fo rc eme n t Division of Fuel Facility and Materials Sa fe ty Inspection Washington, DC 20555 e
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