ML20234C226
| ML20234C226 | |
| Person / Time | |
|---|---|
| Site: | Byron  |
| Issue date: | 09/16/1987 |
| From: | Harrison J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Reed C COMMONWEALTH EDISON CO. |
| Shared Package | |
| ML20234C230 | List: |
| References | |
| NUDOCS 8709210209 | |
| Download: ML20234C226 (3) | |
See also: IR 05000454/1987007
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SEP 161987
Docket No. 50-454
Docket No. 50-455
Commonwealth Edison Company
ATTN: Mr. Cordell Reed
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Senior Vice President
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Post Office Box 767
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Chicago, IL 60690
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Gentlemen.
Thank you for your letter dated August 21, 1987, informing us of the steps you
have undertaken to correct the noncompliance which we brought to your
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attention in our letter dated July 9,1987 regarding Commonwealth Edison's
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snubber reduction program at the Byron facility.
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We have reviewed your responses to violation examples ic, 2b and 2d and will
examine these matters in a future inspection. We have also reviewed your
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responses contesting the validity of the violation examples la, Ib, 2a and 2c
and the severity levels of the two violations. At this time we do not agree
with portions of your response on the following basis:
With regard to Violation la, we do not agree with your statement that Nutech's
walkdown requirements were never less than those previously committed to at
Byron Station. The procedure revision that was being implemented through
May 1987, only addressed those rattle points near critical areas (nozzles,
branch lines and break locations) on the snubber reduction piping itself.
At that time, absolutely no consideration was given for rattle points near
critical areas on any adjacent piping systems.
The flaw in the procedure
that was not recognized by Commonwealth Edison was that during original
construction, all of the rattle points near critical areas eventually would
be reviewed since all of the piping was part of the program.
For the snubber
reduction program, however, a limited number of piping systems were involved
and, as a result, not all potentially affected critical areas were reviewed.
The procedure was eventually corrected by requiring all rattle points on the
snubber reduction piping to be evaluated to verify that critical areas on
adjacent piping systems were not adversely affected as well.
This revision
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was only initiated after the NRC inspector identified the above deficiency.
(It
should be noted that Nutech revised its original "more extensive" walkdown
procedure under the direct guidance of Commonwealth Edison.) Although the
procedure was corrected by the inspection exit meeting, this was more a result
of direct intervention from the NRC inspectors than through initiatives by
CECO.
On this basis, we have concluded that this example of the violation
remains valid.
'With regard to Violation 1b, we do not agree with your statement that seismic
anchor movements need not be considered during seismic interaction walkdowns.
$$$ $&6
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JP
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SEP 161997
Commonwealth Edison Company
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The seismic anchor displacements that are pertinent to this discussion do not
come from the structure, as you suggest, but from the piping to which the
snubber reduction piping is attached or " anchored." This anchor movement is
the inertial movement of the piping attachment point.that is considered the
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boundary for the seismic analysis model.
This movement must be' considered-
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since it is the only way to recouple two different piping analyses that were
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separated for analytical reasons.
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While it m6y be true that most of the piping has insignificant seismic anchor
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displacement, the fact is that certain snubber reduction piping systems were
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" anchored" to piping that was judged to have significant seismic movements.
The procedure as reviewed during May 1987, did not consider these inertial
movements from the attached piping. On this basis, we have concluded that
this example of the violation remains valid.
With regard to Violation 2a, we agree with your statement that there is no
requirement to explicitly address zero period acceleration.
However, zero
period acceleration is a fundamental engineering principle associated with
response spectra analysis and as such can not be ignored. On this basis, we
have concluded that this example of the violation remains valid.
With regard to Violation 2c, we do not agree with your position that the 90%
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stress or insulation criteria were not utilized to resolve interferences.
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The original version of COM-PI-BYR15, " Resolution of Rattle Point Interference
Problems" was being utilized at least until April 1987. As part of this
procedure the resolution criteria for seismic interferences utilized the
90% stress and insulation criteria. Although the final version of COM-PI-BRY21
contained an adequate approach to interference resolution, this change in
methodology was more a direct result of the NRC inspector's intervention than
a result of initiatives by CECO.
On this basis, we have concluded that this
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example of the violation remains valid.
!
Since we have concluded that the above violations remain valid, we further
conclude that both violations should remain classified as Severity Level IV.
The minimal safety significance that you have assigned to these violations
may possibly be attributed to the substantial inspection effort that was
expended by the NRC during the course of the snubber reduction project.
Had
the inspections not taken place until the latter stages of the project, the
significance of these violations may have been increased substantially.
Based on the above discussion, it will be necessary for you to comply with
the provisions of 10 CFR 2.201 for violation examples la, Ib, 2a and 2c and
to submit a written statement describing (1) corrective actions taken and the
results achieved; (2) corrective actions to be taken to avoid further
violations; and (3) the date when full compliance will be achieved for these
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portions of the violations.
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SEP 161987
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- Coninonwealth. Edison Coinpany.
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We appreciate your cooperation in t' is matter.
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Si nce rely , .
yjud Signed by J. J. 'liarrison -
J. J... Harrison, Chief
Engineering Branch
Enclosure: Ltr dtd 8/21/87~
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.cc w/ enclosure:
D.~ Butterfield, Nuclear
Licensing Manager .
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V. I.:,Schlosser,' Project' Manager
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- Gunner Sorensen, Site Project -
Superintendent ,-
.R. E. Querio, Plant Manager.
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~DCS/RSB (RIDS).
-Licensing Fee Management Branch
Resident Inspector, RIII Byron
Resident Inspector, RIII
Braidwood
D. W. Cassel, Jr. , Esq.
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Richard Hubbard
J. W. McCaffrey, Chief, Public
- Utilities Division
. Diane-Chavez, DAARE/ SAFE-
L. Olshan, NRR LPM
H. S. Taylor, Quality Assurance
Division
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RIII
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