ML20210E909
| ML20210E909 | |
| Person / Time | |
|---|---|
| Site: | Catawba  |
| Issue date: | 01/29/1987 |
| From: | Tucker H DUKE POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 8702100394 | |
| Download: ML20210E909 (1) | |
Text
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DUKE POWER GOMPANY e.o. mox aanse CHARLOTTE, N.C. 28242 HALB. TUCKER TELzessown vnos emessemer (704) 373-4531 wuotaan enoswerson January 29, 1987 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D. C.
20555
Subject:
Catawba Nuclear Station RII/BKR Violation 50-413/86-20-01
Dear Sir:
In our response to Violation 50-413/86-20-01 dated November 6, 1986, we committed to megsuring the fraction of beta radiation which penetrates to a depth of 300 mg/cm quarterly at each nuclear station. We request that this frequency be changed to "whenever access to the primary side of any steam generator is available, but no more frequently than quarterly".
We have found that the beta energy spectrum at a station depends upon the nature of the sample used in the measurement and that in the absence of cbvious changes such as high failed fuel, it is remarkably steady for a given sample type. We prefer to use a sample of the radioactivity deposited on reactor coolant system surfaces, and we have found the S/G manway cover to be best. This type of sample yields the dose vs. depth information that is most representative of the beta radiation doses workers receive. Since these samples are available only during outages, the requirement to make measurements quarterly would force us to base some measurements upon evaporated reactor coolant. This would cause fluctuations in the values we
. record for half value layer and penetrating beta fraction.
Such fluctuations would not be indicative of changing plant conditions but rather the result of inconsistent sample types.
We respectfully request approval of this change in our corrective action.
Very truly yours, Hal-B. Tucker 8702100394 870129 LTP/10/sbn
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[ gf xc: NRC Resident Inspector Catawba Nuclear Station l