ML20245C896
| ML20245C896 | |
| Person / Time | |
|---|---|
| Site: | Catawba  |
| Issue date: | 04/21/1989 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20245C895 | List: |
| References | |
| NUDOCS 8904280010 | |
| Download: ML20245C896 (3) | |
Text
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UNITED STATES f
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NUCLEAR REGULATORY COMMISSION i
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E WASHINGTON, D. C. 20655 s,.....,f SAFETY EVALUATION CY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 62 TO FACILITY OPERATING LICENSE NPF-35 l
AND AMENDMENT NO. 56 TO FACILITY OPERATING LICENSE NPF-52 DUKE PCWER COMPANY, ET AL.
CATAWBA NUCLEAR STATION, UNITS 1 AND 2 l
DOCKET NOS. 50-413 AND 50-414
1.0 INTRODUCTION
By letter dated October 5,1988, and supplemented December 30, 1988, and Duke Power Company, et al., (the licensee) prop (a)ed changes January 27, 1989, os to the Catawba Units 1 and 2 Technical Specifications (TSs) to:
allow a one-time waiver to the requirements for a complete diesel generator (DG) overhaul and for the testing as stated in the first footnote to Table 4.8-1, (b) change the counting of failures on DGs from a "per nuclear unit basis" to a "per diesel generator basis" - TS 4.8.1.1.3, and (c) correct the numbers of surveillance referenced in the first footnote to Table 4.8-1.
Each unit at Catawba Nuclear Station has two independent DGs manufactured by IMO Delaval, Incorporated. These DGs are used to provide an emergency standby source of power to the equipment required to safely shutdown the reactor in the event of a loss of offsite power.
2.0 EVALUATION (a) One-Time Waiver to the Requirements of Table 4.8-1 Each DG is controlled by a separate 60 psi pneumatic control system that will trip the engine when the setpoints of various parameters are reached. This process is achieved by the use of six sensors on the engine and one on the control panel. All of these seven sensors are manufactured by California Controls Company, Inc. (Calcon) and are of one particular model Calcar B4400.
The last four valid failures of DG 1A can be attributed to the failure of this Calcon B4400 pressure sensor. These failures took place on April 12, April 19, April 25, and May 5,1988. More information relating to the specifics of these f ailures can be found in the licensee's letter dated May 25, 1988 As stated in its 10 CFR 21 notice of April 29, 1988, and supplemented May 12, 1988, Calcon recommended and approved the remanufacturing of the B4400 sensors. The Catawba sensors were actually remanufactured on site by a Calcon representative. All Calcon B4400 sensors were replaced on DGs with the remanufactured Calcon sensors. Based on the discoveries made by Calcon, it is concluded that the 6th, 7th, 8th, and 9th valid failures within the last 100 valid starts on Unit 1A DG are attributed to the same root cause:
inadequate n
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. design and manufacture of the Calcon B4400 pressure sensors. On October 25, 1988, an invalid failure of DG 1B occurred.
This was not of the sarne failure mode as the failures of DG 1A. More information may be found in the licensee's letter dated November 23, 1988.
The new pressure sensors have been tested, their installation was approved by the manufacturer, and acceptable reliability of DG 1A was demonstrate by 47 valid successful starts since May 5, 1988.
Forty-five of these tests were conducted in accordance with the routine surveillance requirements of 4.8.1.1.2a.4) and 4.8.1.1.2a.5).
The remaining two tests were perforned in accordance with the 184-day testing requirement of 4.8.1.1.2a.4) and 4.8.1.1.2a.5).
The only difference between these two methods is the prelubing of the turbocharger bearings. This is not a significant difference for these anendments because prelubing is not related to the root cause of the four valid failures discussed above.
The root cause was attributed to the inadequate design and manufacture of the Calcon pressure sensors.
It is the licensee's intention to modify the DG trip system. The modifications would delete all pneumatic trip instrumentation from the DGs and replace it with electric trip function. However, these modifications are not connected to the waiver request for rezeroing the four failures on 1A Diesel Generator. The new pneumatic control system pressure sensors were specifically approved by the manufacturer and an accept 6ble reliability of the system has been demonstrated.
In addition, the proposed change would improve the reliability of DG 1A because it would reduce the wear and tear associated with frequent testing.
Based on its review of the licensee's request for a one-time waiver from the requirements of the firr.t footnote to Table 4.8-1, the staff concludes that the request has no adverse impact on safety and would not pose an undue risk to public health and safety. Therefore, it is acceptable.
(b) Change to TS 4.8.1.1.3 Reporting Requirements The proposed change to TS 4.8.1.1.3 would revise the reporting requirement from a per nuclear unit basis to a per DG basis.
Test failures are already determined on a per DG basis as discussed in the footnote to Table 4.8-1.
The reporting requirement is being changed to a per DG basis to be consistent with the testing criteria, and to avoid the need for a dual counting system, one for determining test frequency and one for determining reporting. The testing frequency determination assures that a reliability of 95% is maintained.
Based on its review of the licensee's request for changing the reporting requirement, the staff concludes that the request has no adverse impact on safety and would not pose an undue risk to public health and safety.
Therefore, it is acceptable.
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(c) Correction of typographical errors in Table' 4.8-1 The licensee's proposed changes merely correct the numbers of surveillance referenced in the first footnnte to Table 4.8-1.
The correct surveillance will be referenced. This change is of an editorial nature, and therefore, it is acceptable.
3.0 ENVIRONMENTAL CONSIDERATION
These amendments involve changes to the installation or use of facility components located within the restricted area as defined in 10 CFR Part 20 and changes in surveillance requirements.
The staff has determined that the amendments involve 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 expcsure. The NRC staff has made a determination that the amendments involve no significant hazards consideration, and there has been no public comment on such finding. Accordingly, the amendments meet 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 these amendments.
4.0 CONCLUSION
The Commission made a proposed determination that the amendments involve no significant hazards consideration which was published in the Federal Register (54 FR 7630) on February 22, 1989. The Comission consulted with the state of South Carolina.
No public comments were received, and the state of South Carolina did not have any coments.
We have concluded, based on the considerations discussed above, that:
(1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, and (2) such activities will be conducted in compliance with the Comission's regulations, and the issuance of these amendments will not be inw.ical to the comon defense and security or to the health and safety of the public.
Principal Contributor:
K. Jabbour, PDil-3/DRP-l/II Dated: April 21, 1969
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