ML19312C473
| ML19312C473 | |
| Person / Time | |
|---|---|
| Site: | Oconee, Mcguire, McGuire  |
| Issue date: | 10/08/1976 |
| From: | Moseley N NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | Parker W DUKE POWER CO. |
| References | |
| NUDOCS 7912160001 | |
| Download: ML19312C473 (1) | |
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NUCLCA:t RLGULATORY COMP.1105.
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<% m;,., J' OCT ' 3 378 In Reply Refer To:
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Duke'Pcver Company ATT!!:
Mr. Willia:a 0. Parker, Jr.
Vice President of Steam Production h22 South Church Street P. O. Box 2178 Charlotte, IIorth Carolina 282h2 Gentlemen:
The enclosed Ci'cular 76-05 is forwarded to you for r
action.
If there are any questions related to your under-standing of the actions required, please contact this office.
Sine rely, A
Q.'gy,ftC
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Norman C. Moseli Director ENCLOSURE:
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l Date:
October 8, 1976 IE Circular 76-05 i
If*DRAULIC Sl!0CK AND SWAY SUPPRT.,SSORS - MAINTENANCE OF BLEED AND L0rK-UP VELOCITIES ON ITT GRINNELL'S MODEL NOS. - FIG. 200 AND FIG. 201, CATALOG PH-74-R i
DESCRIPTION OF CIRCU'4 STANCES:
i information has become available related to improper lock-up and Recent j
bleed rates of certain ITT Grinnell shock and sway suppressors (snubbers).
The control block or valve block on the snubbers involved is one which contains the mechanisms for a " dual orifice type" snubber valve arrange-These control blocks or valve blocks can be identified by four ment.
lockinr, nuts on the surface of the block.
These nuts lock the stem of the valve control into position.
Rotation of the stem modifies the l
orifices which control the lockup and bleed rates.
The units in ques-l tion, at this time, are those snubbers which have control block or valve i
block serial numbers from B-0001 through B-2000.
These snubbers include 1 1/2 inch diameter (3 kip capacity) through 6 inch diameter (72 kip capacity) units.
ITT Grinnell first identified this problem in connection with their own testing program during the last two weeks of August 1975.
The origin of the problem was traced by Grinnell to November of 1974 when a design change (known as Revision B) was initiated on Model Nos. - Figure 200 and Figure 201, Catalog PH-74-R snubbers, along with the addition of a Grinnell design specification for lock-up and bleed velocities.
These new rates were to be 8 in/ min. plus or rf ~ts 2 in/ min. for lock-up and 4 in/ min. plus or minus 1 in/ min. for b" At that time production testing of 7.pleted snubbers included in the above series of serial numbers was completed on the basis of "go" or "no-go" testing and did not specific lly determine the lock-up and bleed rates for each snubber.
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DUPLICATE DOCUMENT Entire document previously entered into system under:
ANO 7M/200329 No. of pages:
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