ML19323F729
| ML19323F729 | |
| Person / Time | |
|---|---|
| Site: | Pilgrim |
| Issue date: | 05/16/1980 |
| From: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | Andognini G BOSTON EDISON CO. |
| References | |
| NUDOCS 8005290393 | |
| Download: ML19323F729 (1) | |
Text
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'o UNITED STATES NUCLEAR REGULATORY COMMISSION
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May 16, 1980 Docket No. 50-293 Boston Edison Company M/C Nuclear ATTN:
Mr. G. Carl Andognini, Manager Nuclear Operations Department 800 Boylston Street Boston, Massachusetts 02199 s
Gentlemen:
The enclosed IE Information Notice No. 80-21, " Anchorage and Support of Safety-Related Electrical Equipment," is forwarded to you for information.
No written response is required.
If you desire additional information regarding this matter, please contact this office.
Sincerely, d
W Boyce H. Grier Director
Enclosures:
1.
IE Information Notice No. 80-21 2.
List of Recently Issued IE Information Notices CONTACT:
- 5. D. Ebneter (215-337-5296) cc w/encls:
P. J. McGuire, Pilgrim Station Manager B005290398
t ENCLOSURE 1 SSINS No.: 6870 Accession No.:
UNITED STATES 8005050050 NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON. D.C.
20555 IE Information Notice No. 80-21 Date:
May 16, 1980 Page 1 of 2 ANCHORAGE AND SUPPORT OF SAFETY-RELATED ELECTRICAL EQUIPMENT Description of Circumstances:
l 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 more in-depth evaluation after site visits to several facilities.
The site reviews indicated that equipment was supported in a non-uniform manner.
In some cases, design modifications were required to render acceptable seismic design margins.
The deficiencies in anchorage and support may be due to the fact that earlier engineering design criteria did not require rigorous analyses.
Letters were issued in January 1980 to the SEP plants which requested a review of the anchorage 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 has been identified at Comanche Peak (under construction) in which the welds to the floor supports for the main control panels were found to be undersized and improperly spaced.
Also, the SEP reviewers observed that non-seismic Category I ancillary items (dolleys, gas bottles, block and tackle gear, ductwork, etc.) may be located such that they could potentially dislodge, impact, and damage safety related equipment during an earthquake.
l
e 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 clamping 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 resistance; (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) bolts; (2) sheet metal screws; (3) tack welds; and (4) braced racks.
The potential concern is that 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 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 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.
Facilities 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 time.
If NRC evaluations so indicate, additional actions may be requested or required.
If you have any questions regarding this matter, piease contact the Director of the appropriate NRC Regional Office.
ENCLOSURE 2 IE Information Notice No. 80-21 Date:
May 16, 1980 Page 1 of 1 RECENTLY ISSUED IE INFORMATION NOTICES Information Subject Date Issued to Notice No.
Issued 80-13 General Electric Type SBM 4/2/80 All Power Reactor Facil-Control Switches - Defective ities with an Operating CAM Followers License (OL) or Construction Permit (CP) 80-14 Safety Suggestions from 4/2/80 All Power Reactor Facil-Employees ities with an OL or CP, Fuel Fabrication and Processing Facilities and Materials Priority 1 Licensees 80-15 Axial (Longitudinal) 4/21/80 All Power Reactor Facil-Orianted Cracking in ities with an OL or CP Piping 80-16 Shaft Seal Packing 5/5/80 All Power Reactor Facil-Causes Binding in Main ities with an OL or CP Steam Swing CF Isolation Va' 80-17 Potential Hazards 5/5/80 All R6diographic Licensees Associated With Interchangeable Parts On Radiographic Equipment 80-18 Possible Weapons 5/5/80 All Power Reactor Faci-Smuggling Pouch lities with an OL, Fuel Fabrication and Processing Facilities and Materials Priority I Licensees 80-19 NIOSH Recall of Recir-5/6/80 All Power Reactors with an culation-Mode (Closed-OL, Research Reactors, Fuel Circuit) Self-Contained Facilities and Priority I Breathing Apparatus Material Licensees (Rebreathers) 80-20 Loss of Decay Heat Re-5/8/80 All Power Reactor Faci-moval Capability at lities with an OL or CP Davis-Besse Unit 1 While in Refueling Mode