ML20114A562
| ML20114A562 | |
| Person / Time | |
|---|---|
| Site: | Fort Saint Vrain  |
| Issue date: | 01/09/1985 |
| From: | Alcarez P PUBLIC SERVICE CO. OF COLORADO |
| To: | Johnson E NRC |
| References | |
| NDG-85-0022, NDG-85-22, NUDOCS 8501280278 | |
| Download: ML20114A562 (2) | |
Text
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a INTER-DEPARTMENT MEMO - PUBLIC SERVICE COMPANY OF COLORADO i
NDG-85-0022 DATE:
January 9, 1985
'n CISTRisuttCn
~
BCRST. T. J.
TO:
'P' Letter Distribution BREY. H. L.
BURCHrIELD. B.
CENVER CCC. CCMT.
FROM:
Peggy Alcarez, Nuclear Engineering Division, Diamond Hill mLew:n. M.
EGGEBROTEN. J.
SI"3.'s.".'
ATTN:
GRAMLING. J HOLMES. M. H.
INCEPEMCENT REVIEWER SUBJ:
'P' Letter Replacement Page JCHMS. J ANetSONc E.: H. 3 KITZMAN. A.
. LEE. O. R.
!McBRICE. L. M.
Please replace page 7 of Attachment to P-85003 with the enclosed copy QE"[gj;K-of page 7 of said P letter. The last sentence under e. PSC Response stEHCrr, M. E.
has been completed.
MKQ )
,PORC CLERK
-REESY. J. R.
SINGLETON. L.
TECH SERV. CLERK (3) ol Q
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uRENsCuRG Peggy Alcarez
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Attachment to P-85003 Page 7 temperatures to that for which the CRDM has been i
qualified.
Response
Compensating design and operational modifications are being evaluated.
The installation of seals is being reviewed to detennine the effects of their presence in removing moisture from the CR00A motor area following events where high primary coolant moisture levels are present.
In the event that CR00A temperatures recorded during plant operation prove to be higher than the present qualification temperat tre, 272 degrees F, innediate steps will be taken to perfonn environmental requalification testing on a
CR00A motor assembly.
During requalifiestion, plant operation will be restricted in order to maintain CRDM temperatures below 272 degrees F.
However, CR00As instrumented with temperature devices have been monitored for years and a problem is not expected.
An administrative limit of 250 degrees F is currently in effect at which point Station Manager approval is required to continue operation, d.
NRC Finding:
The present Watt-meter testing of the shim l
E tor during drive-in and. drive-out is not a reliable method to verify full insertion or withdrawal of control rods. This test should be refined or an alternative, reliable test for control rod position verification developed.
t PSC Response: The methodology for the Watt-meter testing referred to is technically sound.
A procedure to more precisely describe the process and provide instructions on how to interpret the data has been prepared.
In addition, methods of increasing the sensitivity of the recording l
instrumentation are being evaluated.
A report on this l
activity will be.
submitted to the NRC by January 31, 1985.
e.
NRC Finding:
Investigate a design change to provide a positive stop on the CRDM position indicator potentiometer shaft to prevent overtravel and provide the results to the NRC.
PSC Response: The concept of either a positive stop or an l
alternate type of position potentiometer is being considered. The problem is that overtravel of the control i
rod damages the existing position potentiometers resulting i
in loss of position indication. Preliminary results favor l
an alternate potentiometer rather than a positive stop.
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