ML19352A104
| ML19352A104 | |
| Person / Time | |
|---|---|
| Site: | Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png |
| Issue date: | 12/27/1976 |
| From: | Switzer D CONNECTICUT YANKEE ATOMIC POWER CO. |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| CYH-3624, IEB-76-05, IEB-76-5, NUDOCS 8103060019 | |
| Download: ML19352A104 (5) | |
Text
Ce n r;i c i< le ;
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Q CONNECTICUT YANKEE ATOMIC POWER COMPANY HADDAM NECK PLANT k
RR v1 BOX 127E. EAST HAMPTON CONN. 06424 December 27, 1976 CYH - 3624 Docket No. 50-213 U. S. Nuclear Regulatory Commission Region I Office of Inspection and Enforcement 631 Park Avenue l
King of Prussia, PA 19406 Attn:
Mr. James P. O'Reilly, Director l
Reference:
Inspection & Enforcement Circular 76-05 dated October 8, 1976 l
Dear Mr. O'Reilly:
Pursuant to your request, the responses to Items 1, 2, and 3 of the referenced document are enclosed as Attachment "A".
l Very truly yours, l
CONNECTICUT YANKEE ATOMIC POWER COMPANY
(-
D. C. Switzer, President DCS:MSM/vad Attachment l
cc:
NRC, Office of Inspection & Enforcement Div. of Reactor Inspection Prcgrams l
Washington, D.C.
20555 1
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ATTACHMENT "A" la.
Provide a list containing each snubber identified and indicate the piping system or component with which it is associated.
Response
SNUBBER VALVE SYSTEM OR SERIAL NO.
SERIAL NO.
COMPONENT 12342 B0368-A4 Feedwater System 12343 B0366-A4 Feedwater System 12345 B0280-A4 Feedwater System 12346 B0367-A4 Feedwater System 12347 B0370-A4 Feedwater System 12348 B0283-A4 Feedwater System 12349 B0374-A4 Feedwater System 12350 B0281-A4 Spare Unit 12351 B0285-A4 Feedwater System lb.
Indicate for each srubber its history of testing and test results as well as its maintenance history.
Response
Snubbers SN 12342, 12343, 12345, 12346, 12347, 12348 and 12349 tested December 23, 1974 at the manufacturers facility according to their procedures FC-39, Revision B and FC-40, Revision A.
Test satisfactory.
Installed in feedwater system June 1975.
No maintenance performed to date.
Snubber SN 12350 tested December 23, 1974 at the manufacturers facility according to their procedures FC-39, Revision B and FC-40, Revision A.
Test satisfactory.
Rejected upon receipt inspection at Connecticut Yankee for visible oil leakage and returned to manufacturer for corrective repairs.
Following necessary repairs, it was returned to Connecticut Yankee and placed in stock as a spare unit.
During the 1976 refueling, it was installed as a replacement for snubber SN 12351.
No maintenance has been performed to date.
Page 1 of 4
ATTACHMENT "A" Snubber SN 12351 tested December 23, 1974 at the manufacturers facility accoroing to their procedures FC-39, Revision B and FC-40, Revision A.
Test satisfactory.
Installed in feedwater system June 1975.
Replaced during 1976 refueling by SN 12350 and sent to manufacturers facility for functional testing as required by Safety Technical Specification 4.13.0.2.
Test results as transmitted by telecen (documentation to follow) were as follows:
OBSERVED DURING TEST Bleed Rate 4.0 in/ min tension 3.5 in/ min compression Lockup Rate 13.2 in/ min tensien 8.6 in/ min compression l
These values were deemed acceptable. Following testing, SN 12351 was re-turned to Connecticut Yankee and is being held as a spare.
ic.
For each snubber list the current required lockup and bleed rates and what rates the snubbers were specified to meet by the original construction /
purchase specification.
Indicate the organization, by name, that was re-sponsible for the preparation of the construction / purchase specification.
Resconse Lockup and bleed rates are not currently required nor were they required l
in the original specifications.
They were purchased as a standard cata-log item in August 1974 and identified as Figure 200, ITT Grinnell Cata-log PH-74, Page PH-134. At the manufacturers they were assembled, filled and tested according to their procedures, FC-39, Revision B, 10-30-72 and FC-40, Revision A, 4-25-72.
Procedure FC-39 specified standard values for calibration of the snubber valves which for the subject snubbers are:
I Pre Closure Compression Velocity 6 - 10 in/ min Set Pressure 22 psi Tension Velocity 6 - 10 in/ min 16.5 psi Post Closure Head End Volume 25.74 ml/ min Rod End Volume 19.30 ml/ min Page 2 of 4
ATTACHMENT "A" Spring Size "A"
Stone and Webster was the organization responsible for design, procurement and installation of the feedwater line restraint system.
Sizing of the snubbers required was based on computer analyses which included considera-tions for thermal and dynamic stresses and loads, as well as locations.
Although these particular snubbers were purchased for installation in the Millstone #2 nuclear plant, because of time considerations, availabil-ity and compatibility of design, they were procured from Millstone for use in the feedline restraint system at Connecticut Yankee.
ld.
If replacement parts are utilized instead of recalibration of the snubbers, provide an assessment of the effect of a bleed rate of 2 inches / minute which represents the new lower bound.
Response
If replacement parts are utilized instead of recalibration of the snubbers, an assessment of the effects of a 2 inches / minute bleed rate will be pro-vided.
2.
For snubbers within the above described series that do not have documentation available defining the lockup and bleed velocities, provide a description of the actions to be taken to substantiate these characteristics. Also, pro-vide the schedule to complete these verifications and modifications, if needed.
Response
During the next refueling outage all of the subject snubbers will be returned to the manufacturer for substantiation of lockup and bleed rates and perfor-mance of any necessary recalibrations and/or modifications.
3.
Review maintenance and modificati:r p on, Jres for the above described series of snubbers where such actions cc M; ef et he performance characteristics of the snubbers.
Such actions inuiude but gre not limited to the'disassem, bly of snubbers, replacement of seals, changing hydraulic fluid and the changing of any valve springs.
Modify the procedures, as appropriate, to assure that any future maintenance or modifications will not change the per-formance characteristics.
Page 3 of 4
o..
a ATTACHMENT "A"
Response
Existing and future plant procedures involving maintenance and modification of the subject snubbers will provide for the avoidance of actions which might change the performance characteristics. Currently, should a snubber require corrective maintenance, other than tightening of fittings and ad-dition of oil to the reservoir, the entire snubber assembly is replaced and returned to the manufacturer for any required work.
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