ML19321A993
| ML19321A993 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 05/16/1980 |
| From: | Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | Eric Turner HOUSTON LIGHTING & POWER CO. |
| References | |
| NUDOCS 8007240505 | |
| Download: ML19321A993 (1) | |
Text
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- UNITED STATES
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611 RYAN PLAZA DRIVE, SUITE 1000 CENTRAL FILES REclow IV E
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ARLINGTON, TEXAS 76012
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.May 16, 1980 In Reply Refer To:
RIV Docket Nos. 50-498/IE Information Notice No. 80-21 50-499/IE Information Notice No. 80-21 Houston Lighting & Power Company ATTN: Mr. E. A. Turner, Vice President Power Plant Construction and Technical Services Post Office Box 1700 Houston, Texas 77001 Gentlemen:
This IE Information Notice is forwarded for information. No written response to this Information Notice is required.
If you have any questions related to this matter, please contact this office.
Sincerely, Y
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l'/.b& k pi
/ r1 V. Seyfrit Director
Enclosures:
1.
IE Information Notice No. 80-21 2.
List of Recently Issued IE Information Notices ScPG7241sfS
s SSINS No.: 6870 Accession No.
UNITED STATES 8005050050 NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT r,
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WASHINGTON. D.C.
20555 IE Information Notice No. 80-2'..
Date: May 16, 1980 Page 1 of 2 ANCHORAGE AND SUPPORT OF SAFETY-RELATED ELECTRICAL EQUIPMENT Description of Circumstances:
Seismic design evaluations in connection with the NRC Systematic Evaluation Program (SEP) have indicated a potential safety deficiency in the anchorage and support of safety-related electrical equipment.
This subject was high-lighted for mora in-depth evaluation after site visits to several facilities.
The site reviews indicated that equipment was supported in a non-uniform In some cases, design modifications were required to render acceptable manner.
seismic design margins. The deficiencies in anchorage and support may be due to the fact that earlier engineering design criteria did not require rigorous anclyses.
Letters were issued in January 1980 to the SEP plants which requested a review of the anEhorage of safety-related electrical equipment.
The findings from the reviews at Haddam Neck, Big Rock Point, Dresden 2, Oyster Creek, and Palisades identified various safety-related electrical equipment that did not have positive anchorage. The reviews at other SEP plants are continuing. A summary is provided below of those items so far identified.
Station Service Transformers Motor Control Centers (4160 V - 480V)
Cable Trays DC to AC Inverters Computer Emergency Diesel Generator Control Panels - MG Set Room Heater
- Air Compressor Batteries - Emergency Diesel
- Control Room Generator Instrument Rack
- Diesel Fire Pump Battery Room Main Breaker and
- Station Distribution Panel Station Battery Rack A related item Las been identified at Comanche Pr. (under construction) in which the welds to the floor supports for the r9in :on;Jol panels were found to be undersized and improperly spaced.
Al a:, ' br 3EP reviewers observed that non-seismic Category I ancillary items (dc:lejk
- )., bottice, block and tackle t
gear, ductwork, etc.) may be located such (pat they could potentially dislodge, impact, and damage safety-related equipment during an certhscake.
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IE Information Notice No. 80-21 Date: May 16, 1980 Page 2 of 2 The type of anchorage systems utilized in the SEP plants and their expected capacities vary widely. For example, high uncertainty exists relative to the capacity of non-engineered tack welds and attachments that rely on frictional clasping forces.
In some cases, equipment has been found free standing with no means of positive lateral support.
(Friction being the only lateral load carrying mechanism). Most often, heavier equipment is anchored using (1) tack welds to steel angles embedded in concrete; (2) clips that rely on frictional ret' stance; (3) concrete embedded anchor bolts; or (4) external braced frames.
Lighter equipment housed in cabinets or attached to panels or racks has been anchored using (1) Aolts; (2) sheet metal screws; (3) tack welds; and (4) braced racks.
The potential concern is tnat certain pieces of equipment may not have adequate levels of seismic resistance capability due to limited anchorage capacity.
The potential problems relate to overturning and/or sliding of large equipment j
and gross movement or unacceptable forces on smaller attached equipment that may render it inoperable during an earthquake.
For certain large battery racks, this judgment is supported by analysis that predict unacceptable seismic j
behavior.
Section 3.10 of the Standard Review Plan provides acceptance criteria for the seismic qualification of Category I electrical equipment.
These criteria include IEEE Std. 344, " Guide for Seismic Qualification of Class 1E Electrical Equipment-for Nuclear Power Generating Stations," first issued in 1971.
Pacilities designed before about 1971 without benefit of such design and testing criteria may have some anchorage deficiencies.
The NRC staff is continuing to evaluate this issue on the SEP plants as part of the seismic review in the SEP. Remedial actions have been planned for the affected plants.
This Information Notice is provided as notification of a possibly significant matter.
It is expected that recipients will review the information for possible applicability to their facilities.
No specific action or response is requested at this tise.
If NRC evaluations so indicate, additional actions ray be requested or required.
If you have any questions regarding this matter, pleast contact the Director of the appropriate NRC Regional Office.
IE Information Notice No. 80-21 May 16, 1980 LISTING OF RECENTLY ISSUED IE INFORMATION NOTICES Information Subject Date Issued To Notice No.
Issued 80-15 Axial (Longitudinal) 4/21/80 All light water reactor Oriented Cracking In facilities holding power Piping reactor Operating Licenses (OLs) or Construction Permits (cps) 80-16 Shaft Seal Packing causes 4/29/80 All power reactor BindinS in Main Steam facilities in your Swing Check and Isolation Region with an OL or Valves CP 80-17 Potential Hazards Associated 5/5/80 All radiography With Interchangable Parts Licenses On Radiographic Equipment 80-18 Possible Weapons Smuggling 5/5/80 All power reactor Pouch facilities with oa Operating License (OL), fuel fabrication and processing facilities and Materials Priority I licensees (processors and distributors) 80-19 NIOSH Recall of Ricircu-5/6/80 All holders of a lating-Mode (Closed Circuit) power reactor Operating Self-Contained Breathing License (OL), Research Apparatus (Rebreathers)
Reactor License, Fuel Cycle Facility License and Priority I Material License 80-20 Loss of Decay Heal Removal 5/8/80 All light water reactor Capability at Davis-Besse facilities holding Unit 1 While in a Refueling power reactor Operating Mode Licenses (OLs) or Construction Permits (cps) l Enclosure
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