ML19211D177
| ML19211D177 | |
| Person / Time | |
|---|---|
| Site: | La Crosse File:Dairyland Power Cooperative icon.png |
| Issue date: | 01/01/1980 |
| From: | Eisenhut D Office of Nuclear Reactor Regulation |
| To: | Linder F DAIRYLAND POWER COOPERATIVE |
| References | |
| TASK-03-06, TASK-3-6, TASK-RR NUDOCS 8001160678 | |
| Download: ML19211D177 (5) | |
Text
__
/
'o't UNITED STATES NUCLEAR REGULATORY COMMISSION E
WASWNGTON, D. C. 20555
.o January 1, 1980 Docket No. 50-409 Mr. Frank Linder General Manager Dat<yland Power Cooperative 2615 Eut Avenue South Lacrosse, Wisconsin 54601
Dear Mr. Linder:
Recent seismic design evaluations conducted in the Systematic Evaluation Program (SEP) have indicated a potenti!ti safety concern relative to the anchorage and support of safety related electrical equipment.
It has also been observed that non-seismic Category I auxiliary items (dolleys, gas bottles, etc.) may be dislodged by an earthquake and damage safety related equipment. These issues were identified during site visits to Dresden 2, Haddam Neck, Ginna, Oyster Creek, Palisades and Millstone 1 by review teams consisting of NRC representatives and consultants. Since operability of the subject equipment may be essential during and after a seismic disturbance, we request that you assess the capability of all safety related electricai equipment (as well as non eismic Category I auxiliary items) to resist seismic forces and implement remedial measures, as necessary, to increase safety margins. All operating licensees of nuclear power facilities are being notified of this issue by an I&E Information Notice (Enclosure 1).
Within 30 days, you are requested to develop an action plan for resolution of this issue and to submit it for our review. The following issues should be addressed:
1.
Does positive anchorage exist (load carrying mech 6aism other than friction);
2.
If positive anchorage exists, has the anchorage system been engineered with adequate capacity; and 3.
Was the anchorage fabricated to quality standards?
The results of your investigation of Item I should be submitted within 60 days of the date this letter is received.
It shculd describe any corrective action considered necessary. The cverall issue, including any required mooifications, should be resolved by September 1,1980.
1757 056
. Although the final seismic design basis for your facility has not been resolved, and other changes may be required, appropriate action on this matter should not be delayed.
If necessary, consideration should be given to providing temporary supports with more pennanent supports being installed after all seismic questions have been resolved.
Si ncere'.y,f
%OlGU diill LLf
'Darrell G. Eisenhut, Acting Director Division of Operating Reactors Office of Nuclear Reactor Regulation
Enclosure:
As stated cc w/ enclosure:
See next page 1757 057
. cc w/ enclosure:
Fritz Schubert, Esquire Director, Technical Assessment Staff Attorney Division Dairyland Power Cooperative Office of Radiation Programs 2615 East Avenue South (AW-459)
La Crosse, Wisconsin 54601 U. S. Environmental Protection Agency
- 0. S. Heistand, Jr., Esquire Crystal Mall #2 Morgan, Lewis & Bockius Arlington, Virginia 20460 1800 M Street, N. W.
Washington, D. C.
20036 U. S. Environmental Protection Agency Mr. R. E. Shimshak Federal Activities Branch La Crosse Boiling Water Reactor Region V Office Dairyland Power Cooperative ATTN:
EIS C00RDINAT)R P. O. Box 135 230 South Dearborn S.reet Genoa, Wisconsin 54632 Chicago, Illinois 60604 Coulee Region Energy Coalition Charles Bechhoefer, Esq., Chairman ATTN: George R. Nygaard Atomic Safety and Licensing Board P. 0. Box 1583 U. S. Nuclear Regulatory Commission La Crosse, Wisconsin 54601 Washington, D. C.
20555 La Crosse Public Library Dr. George C. Anderson 800 Main Street Department of Oceanography La Crosse, Wisconsin 54601 University of Washington Seattle, Washington 98195 Mrs. Ellen Sabelko Society Against Nuclear Energy Mr. Ralph S. Decker 929 Cameron Trail Route 4, Box 1900 Eau Claire, Wisconsin 54701 Cambridge, Maryland 21613 Town Chairman Town of Genoa Route 1 Genoa, Wisconsin - 54632 Chairman, Public Service Commission of Wisconsin Hill Farms State Office Building Madison, Wisconsin 53702 1757 058
UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
20555 NOVEMBER
,1979 IE Information Notice No. 79-ANCHORAGE AND SUPPORT OF SAFETY RELATED ELECTRICAL EQUIPMENT Description of Circumstances Recent seismic design evaluations in connection with the NRC Systematic Evaluation Program (SEP) have incicated a potential safety deficiency relative to the anchorage ano support of safety related electrical equip-ment. This subject was highlighted for more in-cepth evaluation after site visits to several facilities. These reviews have inoicated that equipment is supported in a non-uniform manner. This may have resulted from the fact that earlier engineering design criteria did not require rigorous analyses.
Further evaluaticns are continuing for tne SEP plant designs.
In some cases, design moaifications may be required to render acceptable seismic design margins.
In general, a lack of engineered supports of safety related electrical equip-ment has been observeo at certain SEP plants. Typical components affected include:
-AC and DC motor control centers
-transformers
-switch gear
-i nverters
-control room panels
-battery racks
-instrument panels
-cable trays Also, a related observation indicates that non-seismic Category I ancillary items (colleys, gas bottles, block ano tackle gear, ductwork, etc.) are located such tnat they may dislodge, impact ano damage safety related equipment during an earthquake.
The types of anchorage systems utilized in these plants and their expected capacities vary widely. For exanple, high uncertainty exists relative to the capacity of non-engineered tack welds ano 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 carryng mechanism). Most of ten, heavier equipment is anchored using 1) tack welds to steel angles embeaded in concrete; 2) clips that rely on frictional resistance; 3) concrete embedded anchor bolts; or
- 4) external braced f rames. Lighter equipment housed in cabinets or attached to panels or racks has been anchored using 1) bolts; 2) sheet metal screws; 3) tack welas; and 4) braced racks.
1757 059
~-
. c.
2-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 judgement is supported by computations that predict unacceptable seismic behavi or.
Secticn 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 1 Electrical Equipment for Nuclear Power Generating Stations", first issued in 1971. Facili-ties 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 action has been taken on one SEP plant to date.
This Information Notice is provided as an early notification of a possible significant matter.
It is expected that recipients will review the design criteria for anchorage and support of safety related electrical equipment including as-built installation details to assure adequate capability to resist seismic forces. No written response is required.
If you have any questions regarding this matter, please contact the Director of the appropriate NRC Regional Office.
1757 000 9
- _