ML20206R838
| ML20206R838 | |
| Person / Time | |
|---|---|
| Site: | Catawba  |
| Issue date: | 01/14/1999 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20206R825 | List: |
| References | |
| NUDOCS 9901200284 | |
| Download: ML20206R838 (3) | |
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UNITED STATES y
j NUCLEAR REGULATORY COMMISSION t
WASHINGTON. D.C. 2055MX)01
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO.
174 TO FACILITY OPERATING LICENSE NPF-35 AND AMENDMENT NO. 166 TO FACILITY OPERATING LICENSE NPF-52 DUKE ENERGY CORPORATION. ET AL.
CATAWBA NUCLEAR STATION. UNITS 1 AND 2 DOCKET NOS. 50-413 AND 50-414
1.0 INTRODUCTION
On November 11,1998, Duke Energy Corporation (DEC, the licensee) requested that Surveillance Requirements (SRs) 3.6.11.6 and 3.6.11.7 be revised. DEC has determined that these SRs, as they currently stand, are not in agreement with the existing design. The staff's review of DEC's proposed revision is set forth below.
2.0. DISCUSSION AND EVALUATION As stated in the Catawba Final Safety Analysis Report (FSAR) Section 7.6.5 and the Catawba Updated Final Safety Analysis Raport (UFSAR), Section 7.6.4, the function of the Containment Pressure Control System (CPCS) is to protect the containment building from excessive l
depressurization by preventing inadvertent actuation or continuous operatior, of the Containment Spray System (CSS) and Air Return System (ARS) when containment pressure is at or less than the CPCS permissive setpoint. Details of the design of the CPCS are discussed in the cited sections of the FSAR or UFSAR. The staff approved the CPCS design in j
Section 7.3.2.10 of the Catawba Safety Evaluation Report (NUREG-0954, dated February 1983).
The control scheme of the CPCS is comprised of eight independent control circuits (four per train), each having a separate and independent pressure transmitter and current alarm module.
Each pressure transmitter monitors the containment pressure and provides input to its respective current alarm. The current alarms are set to inhibit or terminate the CSS and the ARS when containmen'. pressure falls to or below 0.25 psig. The alarm modules switch back to the permissive state (i.e., allow the CSS and ARS to operate) when the containment pressure is l
greater than or equal to 0.45 psig.
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2.1 SR 3.6.11.6 l
This SR currently requires DEC, every 18 months, to " Verify that each ARS fan is de-energized or is prevented from starting upon receipt of a terminate signal from the containment Pressure Control System (CPCS)."
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DEC proposed to add a phrase at the end of this requirement "and is allowed to start upon receipt of a start permissive from the CPCS." The revised SR would require testing of all relevant CPCS functions associated with allowing the fans to start and deenergizing or 9901200284 990114 PDR ADOCK 05000413 P
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preventing them from starting. Currently, in the absence of this phrase in SR 3.6.11.6, the licensee has imposed such requirement by plant procedures.
Figure 7-14 of the UFSAR shows that the ARS fan receives both a strt permissive and a stop or terminate signal from the CPCS. The licensee's proposed phrase would, therefore, accurately reflect the current design of the CPCS. Furthermore, the prcposed phrase does not involve any change to the current design of the CPCS. The proposed phrase is an additional requirement to verify the operability of the system, and the staff finds it acceptable.
2.2 SR 3.6.11.7 This SR currently requires DEC, every 18 months, to " Verify that ARS fan motor-operated damper closes or is prevented from opening upon receipt of a terminate signal and is allowed to open upon receipt of a start permissive from the Containment Pressure Control System (CPCS)."
A design change was made in 1994 under 10 CFR 50.59, in accordance with DEC's Nuclear Station Modification CN-11321. A summary of CN-11321 is found in DEC's submittal, W. R.
McCollum to NRC, March 27,199[6], NRC Accession 9604010373. After the 1994 design modification, the ARS fan motor-operated damper does not receive a close or terminate signal from the CPCS. Therefore, DEC proposed to delete that portion of the SR pertaining to l
verification of damper closing, and to replace the reference to receipt of a terminate signal with a reference to the absence of a start permissive signal. The current SR 3.6.11.7 does not fully l
reflect the current CPCS design. The proposed change would bring this SR to conformity with the current design of the CPCS: the UFSAR, and specifically Figure 7-14 show that the ARS fan motor-operated damper receives an open permissive from the CPCS, but not a close or terminate signal. DEC stated that the ARS design does not require motor-operated damper closure due to the fact that the fan will stop when required and the check damper is closed when the fan is not operating.
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The staff reviewed DEC's proposed surveillance requirement against the design described in the UFSAR, and reviewed DEC's CN-11321. The staff agrees that the proposed SR would reflect the current design of the CPCS, and is, therefore, acceptable.
3.0 STATE CONSULTATION
in accordance witn the Commission's regulations, the South Carolina State official, Mr. Virgil l
Autrey, was notitied of the proposed issus ice of the amendments. The State official had no comments.
4.0 ENVIRONMENTAL CONSIDERATION
The amendments change surveillance requirements. The NRC staff has determined that the amendments involve no significant increase in the amounts, no significant change in the types of ar y effluents that may be released offsite, and tnat there is no significant increase in individual or cumulative occupational radiation exposure. The staff has previously issued a proposed finding that the amendments involve no significant hazards consideration, and there has been no public comment on such finding (63 FR 66591 published December 2,1998).
3-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 environmentalimpact statement or environmental assessment need be prepared in connection with the issuance of the amendments.
5.0 CONCLUSION
The staff has concluded, based on the considerations discussed above, that: (1) there is i
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 amendments will not be inimical to the i
common defense and security or to the health and safety of the public.
j Principal Contributors: H.Li P. Tam Date:
January 14, 1999 l
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