ML19327A112
| ML19327A112 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 07/07/1980 |
| From: | Mattimoe J SACRAMENTO MUNICIPAL UTILITY DISTRICT |
| To: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| References | |
| IEB-80-11, NUDOCS 8008010166 | |
| Download: ML19327A112 (3) | |
Text
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': SMUD SACRAMENTO MUNICIPAL UTILITY DISTRICT O 6201 s street, Box 15830, sacramento, California 95813; (916) 452-3211 July 7, 1980
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Mr. R. H. Engelken, Director
";'.s Region V, Office of Inspection
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'D and Enforcement U.S. Nuclear Regulatory Commission Suite 202, Walnut Creek Plaza 1990 North Californ~ia Boulevard Walnut Creek, CA 94596 Docket 50-312 Rancho Seco fluclear Generating Station, Unit No.1 IE Bulletin 80-11 Masonry Wall Design
Dear Mr. Engelken:
The subject bulletin, dated May 8,1980, requested information on masonry walls that could affect safety related systems. Attachment 1 provides our response to the program for reevaluating the masonry walls.
This work will be conducted and a final report will be filed within the time frame allowed in the bulletin.
If you require additional information, please contact us.
Sincerely yours, b{
Jt. RWA John J. Mattimoe Assistant General Manager and Chief Engineer Attachment cc: Office of Inspection and Enforcement Division of Reactor Operations Inspection Nuclear Regulatory Commission Washington, D.C.
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i RESPONSE TO I & E BULLETIN 80-11 MASONRY HALL DESIGN 1.
Identify all masonry walls in your facility which are in proximity to or have attachments from safety-related piping or equipment such that wall failure could affect a safety-related system.
Describe the systems and equipment, both safety and non-safety-related, associated with these masonry walls.
Include in your review, masonry walls that are intended to resist impact of pressurization loads, such as missiles, pipe whip, pipe creak, jet impinge-ment, or tornado, and fire or water barriers, or shield walls.
Equipment to be considered as attachments or in proximity to the walls shall include, but is not limited to, pumps, valves, motors, heat exchangers, cable trays, cable / conduit, HVAC ductwork, and electrical cabinets, instrumentation and controls. Plant surveys, if necessary, for areas inaccessible during normal plant operation shall be performed at the earliest opportunity.
Antwer: Two areas at th'e Rancho Seco Nuclear Generating Station, Unit #1 have reinforced concrete masonry block walls and both areas are external to the structures.
1.
rea 1 is located at the 40-foot elevation of the Auxiliary Building and is of a three-sided configuration.
It encloses the Nuclear Station Service Transformer Train "B".
No equip-ment, pipes, or safety-related conduit is attached to the walls.
2.
Area 2 is located on the North side of the power block structures.
The safety-related equipment located in proximity of eight foot high concrete masonry block wall, that possibly could be affected by the' wall failure are the Train "B" Nuclear Service cooling water heat exchanger and pump, the Cardox Co2 storage unit, the under-ground diesel oil storage tank, and possibly the condensate storage tank.
No equipment is on the wall except the conduit for the intrusion alarm system for the area.
2.
Provide a reevaluation of the design adequacy of the walls identified in Item 1 above to determine whether the masonry walls will perform their intended function under all postulated loads and load combinations.
In this regard, the NRC encourages the formation of an owners' group to establish both appropriate reevaluation criteria and where necessary, a
.later confirmatory masonry test program to quantify the safety margins established by the reevaluation criteria (this is discussed further in Item 3 below).
a.
Establish a prioritized program for the reevaluation of the masonry walls.
Provide a description of the program and a detailed schedule for completion of the reevaluation for the categories in the program.
The completion date of all reevaluation should not be more than 180 days from the date of this Bulletin. A higher priority should be j
L.
I
3
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I placed on the wall reevaluations considering safety-related piping 2-1/2 inches or greater in diameter, piping with support loads due to thermal expansion greater than 100 pounds, safety-related equipment weighing 100 pounds or greater, the safety significance of_ the poten-tially affected systems, the overall loads on the wall, and the oppor-tunity for performing plant surveys and, if necessary, modifications in areas othenvise inaccessible.
The factors described above are meant to provide guidance in determining what loads may significantly affect the masonry wall analyses.
Answer: The field investigation of the two areas will be completed during the week of July 7,1980. The Area I walls will be analyzed starting July 15, 1980 to verify the structural design of_these walls.
Concurrently with the reanalysis, construction documentation will be assembled. This effort for Area I will be complete by August 29, 1980. The Area 2 walls reanalysis will be started on August 1,1980. Con-currently, the construction data will be assembled. This effort will be complete by October 1, 1980. The final report will be prepared and submitted by 180 days from the date if the bulletin.
3.
Existing test data or conservative assumptions may be used to justify the reevaluation acceptance criteria if the criteria are shown to be conservative and applicable for the actual plant conditions.
In the absence of. appropriate acceptance criteria, a conformatory masonry
' wall test program is required by the NRC in order to quantify the safety margins inherent in the schedule to justify the reevaluation criteria used in Item 2.
If a test program is necessary, provide your commitment for such a program and a schedule for completion of the pro-gram. _This test program should address all appropriate loads (seismic, tornado, missile,etc.).
It is expected that the test program will extend beyond the 180 day ~ period allowed for the other Bulletin actions.
Submit the results of the test program upon its completion.
Answer:
Justification for the reevaluation criteria will be submitted with the reevaluation report within.180 days of the date of the Bulletin received.
Justifications will be based on reference to effective codes and esta-blished standards of practice related to concrete and masonry design typically used throughout the industry.
It is anticipated that such justification will be considered appro-priate, and that a test program will not be necesrary, except as required to determine project unique structural properties such as collar joint strength, and any other properties for which construction test data is not available or can not otherwise be determined.
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