ML18010A764
| ML18010A764 | |
| Person / Time | |
|---|---|
| Site: | Harris  |
| Issue date: | 09/08/1992 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML18010A763 | List: |
| References | |
| NUDOCS 9209160093 | |
| Download: ML18010A764 (3) | |
Text
~y,S atop~
,~C Wp,
+
O~
Cy I
nO lA L
0
+r+~
gO
++*++
UNITED STATES UCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 32 TO FACILITY OPERATING LICENSE NO.
NPF-63 CAROLINA POWER Ec LIGHT COMPANY SHEARON HARRIS NUCLEAR POWER PLANT UNIT 1
DOCKET NO. 50-400
- 1. 0 INTRODUCTION By letter dated December 16,
- 1991, the Carolina Power 8 Light Company (the licensee) submitted a request for changes to the Shearon Harris Nuclear Power Plant, Unit 1, Technical Specifications (TS).
The amendment revises TS 4.2.3.5 so the allowable time period for the use of calibrated instrumentation utilized in the performance of the reactor coolant system (RCS) calorimetric flow measurement would be increased from 7 to 21 days.
2.0 BACKGROUND
The reactor coolant system (RCS) flow rate is required to be verified at the beginning of each cycle with a precision primary and secondary energy balance.
This precision energy balance relies on instrumentation for measuring RCS and secondary system parameters which must first be calibrated.
The time period between this calibration and performance of the energy balance may have an effect on the accuracy of the RCS calorimetric flow measurement because the instruments used may drift during this period.
WCAP-12340, "Westinghouse Improved Thermal Design Procedure Instrumentation Uncertainty Methodology for Carolina Power 8
Light Company Shearon Harris Nuclear Power Station," documents the 2. 1 percent uncertainty allowance to measured flow rate.
This allowance includes the uncertainty associated with performing the precision flow calorimetric uncertainty plus the uncertainty associated with measuring flow with cold leg elbow taps during operation.
The flow measurement uncertainty of 2. 1 percent is based on no drift of the calibrated instrumentation with the assumption that the flow measurement is performed within 30 days of calibrating the measurement instrumentation.
To assure that there would be no drift, the current TS 4.2.3.5 specifies that the calibrated instruments would be used within 7 days of their being calibrated.
However, the 7 day limitation has proved to be too restrictive and the licensee proposes to change the limitation from 7 days to 21 days.
9209160093 920908 PDR ADOCK 05000400 p
- 3. 0 EVALUATION The 2. 1 percent flow measurement uncertainty was determined assuming that the flow measurement is performed within the calibration (or guaranteed accuracy) period for the measurement instrumentation and, therefore, does not include a penalty calibration drift.
Currently, 7 days is designated in TS 4.2.3.5 as the calibration period.
However, the analyses in WCAP-11168, Revision 1,
and WCAP-
- 12340, which provide the basis for the 2. 1 percent flow measurement uncertainty, allow a calibration period of up to 30 days before a drift penalty is required.
Therefore, the request to revise the allowable time period from 7 days to 21 days for the calibration of instrumentation utilized in the performance of the RCS calorimetric flow measurement is justified because the 21 day period falls well within the 30 day analysis value documented in WCAP-12340.
In addition, a
December 16, 1991, letter from G.
E. Vaughn, CPL, to the NRC states that an analysis of vendor transmitter test data shows that any increase in instrument drift between 7 days and 21 days is negligible.
We, therefore, find the change to 21 days to be acceptable.
4.0
SUMMARY
The staff has reviewed the proposed change in TS 4.2.3.5 to increase the maximum calibration period of the measurement instrumentation used for the precision energy balance from 7 days to 21 days and found it to be acceptable.
5.0 STATE CONSULTATION
In accordance with the Commission's regulations, the State of North Carolina official was notified of the proposed issuance of the amendment.
The State official had no comments.
- 6. 0 ENVIRONMENTAL CONSIDERATION The amendment changes a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20.
The NRC staff has determined that the amendment involves no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure.
The Commission has previously issued a proposed finding that the amendment involves no significant hazards consideration, and there has been no public comment on such finding (57 FR 6035).
Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9).
Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendment.
~~
I
- 7. 0 CONCLUSION The Commission has concluded, based on the considerations discussed
- above, that (I) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed
- manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public Principal Contributor:
H. Balukjian September B, f992