ML20036C142
| ML20036C142 | |
| Person / Time | |
|---|---|
| Site: | Byron  |
| Issue date: | 06/07/1993 |
| From: | Chrzanowski D COMMONWEALTH EDISON CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| IEB-93-002, IEB-93-2, NUDOCS 9306140295 | |
| Download: ML20036C142 (3) | |
Text
,
.Ccmmonwsalth Edison O
1400 Opus Place s -
O Downers Grove, Illinois 60515 June 7,1993 U.S. Nuclear Regulatory Commission Washington, DC 20555 Attention: Document Control Desk
Subject:
Byron Station Response to Bulletin 93-02, " Debris Plugging of Emergency Core Cooling Suction Strainers."
Byron Station Units 1 and 2, (NRC Docket Numbers 50-454 and 50-455)
The purpose of this letter is to provide the Byron Station response to the subject Bulletin. The details of the response are contained in the attachment. In summary, Byron Station has performed the requested actions of the Bulletin.
Because no fiberous air filters or other temporary sources of fibrous material, not designed to withstand a LOCA, were identified at Byron Units 1 and 2, no compensatory measures were required. Bulletin compliance was verified by a combination of visual examinations and review of administrative controls.
To the best of my knowledge and belief, the statements contained in this document are true and correct. In some respects these statements are not based on my personal knowledge, but on information furnished by other CECO employees, contractor employees, and/or consultants. Such information has been reviewed in accordance with company practice, and I believe it to be reliable.
If there are any questions or comments, please contact me at (708) 663-7292.
r Sincerely, j
Stato of
. County of MS Sic ed befo e on this E day of UML.19 by NO C
~
tary Public /
7 David J.
hrzanowski f '
Nuclear Regulatory Services Attachments: Byron Station Response to Bulletin 93-03, cc: J.B. Martin, Regional Administrator-RIII
NOTARY PUBUC. STATE OF ILUNO S
+
MY COMMISSION EXPIRES 6/25/94 i
DTannT 9306140295 930607 D
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ATTACHMENT s
BYRON STATION RESPONSE TO BULLETIN 93-02 i
i The purpose of this report is to document Byron Station's compliance with NRC Bulletin 93-02, Debris Plugging of Emergency Core Cooling Suction Strainers, for Units 1 & 2.
The Bulletin was issued on May 11,1993 and requires licensees to identify fibrous air filters or other temporary sources of fibrous material, not designed to withstand a LOCA, which are installed or stored inside Containment. For operating units this material must be ren2cved within 120 days and for shutdown units this material must he removed prior to restart.
Byron Station's only use of fibrous filter material inside the Unit 1 & 2 containments is the containment charcoal filters which are designed to be Seismic Category I and are not required during a LOCA. They are only used for habitability of personnel when necessary. The prefilters in the containment charcoal filters contain fibrous filter material and have a HEPA and charcoal filter downstream to remove any fibrous material during operation. Also, the inlet dampers to the containment charcoal filters are fail closed to prevent moisture reaching the prefilters during a LOCA. Any moisture and fibrous filter material would be maintained in the prefilter section because the drains are normally capped on the prefilter and HEPA sections of the containment charcoal filters. Additionally, no temporary filters of any type or fibrous materials are allowed to be stored inside containment during power operations.
All insulating material used in Unit 1 & 2 containments is of the metallic reflective type per Sargent & Lundy Design Specification F/L 2816 Installation of Metallic Insulation which is in accordance with NUREG 0897 Rev.1, Containment Emergency Sump Perfbrmance. Metallic reflective insulation produces no fibrous debris of concern to the Emergency Core Cooling system suction strainers.
Also stainless steel lagging.010" thick is used as a replacement for carbo-zinc coating on the Unit I containment chilled water piping inside contaimnent but outside the secondary shield wall. This laggingis banded on the containment chilled water piping between the containment wall and the Reactor Containment Fan Cooler enclosures. It would not generate any fibrous material and would remain outside the secondary shield wallifit became dislodged from the piping, i
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NI'TACIIMENT BYRON STATION RESPONSE TO BULLETIN 93-02 1,2BVS 5.2.d.2-1, Unit 1&2 Visual Inspection of the Containment Recirculation Sumps, and 1,2BOS 5.2.c-1, Unit 1&2 Containment Loose Debris Inspection verify the cleanliness of the ECCS suction strainers and the remaining containment area. This ensures cleanliness of the ECCS suction strainers and the remaining containment area from foreign material including fibrous debris. In response to NRC Bulletin I
93-02 and as a check of our administrative controls,2BVS 5.2.d.2-1 was satisfactorily performed on 5-12-93 and the 1BVS 5.2.d.2-1 performed following BIR05 was reviewed with no identified concerns. Also, the 1 and 2BOS 5.2.c-1 for the mode 5 to 4 change to establish containment integrity following the last respective refueling outages were reviewed with no identified concerns.
In addition, the topic of plugging of Emergency Core Cooling System (ECCS) suction strainers has been previously reviewed for IEN 88-28, Potential For Loss Of i
Post-LOCA Recirculation Capability due to Insulation Debris Blockage, IEN 89-77, j
Debris in Containment Emergency Sumps and Incorrect Screen Configurations, and IEN 92-71 Partial Plugging of Suppression Pool Strainers at a Foreign BWR. These l
extensive reviews have verified the adequacy of the design and administrative controls of the Emergency Core Cooling system (ECCS) suction strainers at Byron Station.
In conclusion, Byron Station Units 1&2 have no identified fibrous or filters or other temporary sources of fibrous material not designed to withstand a LOCA installed or stored in their containments. Therefore, no compensatory or prompt removal actions are required of Units 1&2.
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