ML20215M937
| ML20215M937 | |
| Person / Time | |
|---|---|
| Site: | Catawba  |
| Issue date: | 10/28/1986 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20215M921 | List: |
| References | |
| NUDOCS 8611030509 | |
| Download: ML20215M937 (3) | |
Text
_
!e ncy'e
~
UNITED STATES f
NUCLEAR REGULATORY COMMISSION
.p WASHINGTON, D. C. 20555
%...../
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT N0.18T0 FACILITY OPERATING LICENSE NPF-35 AND AMENDMENT N0. 8 TO FACILITY OPERATING LICENSE NPF-52 CATAWBA NUCLEAR STATION, UNITS 1 AND 2 DUKE POWER COMPANY, ET AL.
INTRODUCTION By letter dated August 4,1986, Duke Power Company, et al., (the licensee) proposed changes to Technical Spect.fications (TS) Tables 3.6-1, 3.6-2a and 3.7-1 for Catawba Nuclear Station, Units 1 and 2.
The changes to Tables 3.6-1 and 3.6-2a were necessary to include the addition of a containment penetration and a containment isolation valve which was planned during the current Unit I refueling outage.
In the August 22, 1986, letter, the licensee stated that due to schedular constraints the penetration and valve will not be added during this refueling outage. Thus, the following eval-uation only addresses the change to TS Table 3.7-1 which is necessary in order to allow setooint testing of the main steam relief valves that were all termed " inoperable" due to the replacement of the springs. Furthermore, the September 17 and October 6,1986, letters clarified the TS change request and proposed to: (1) restrict the reactor operation to no greater than Mode 3 (i.e., reactor suberitical, Hot Standby), (2) to make the change ap for one time only for each Unit, prior to entering Mode 2 (Startup)plicable following the first refueling outage, and (3) to reduce the high trip setpoint of the power range neutron flux monitor from 109% to 2% of rated thermal power to provide further protection in addition to item (1) above that restricts reactor operation to no greater than Mode 3 (i.e., reactor subcritical).
j EVALUATION TS Table 3.7-1 specifies the maximum allowable power range neutron flux high setpoint (percent of rated thermal power) for inoperable safety valves on any operating steam generator. Previously, the lowest setpoint was 43 percent rated thermal power for three inoperable safety valves. During the current refueling outage the licensee (at the manufacturer's recommendation) is planning to replace the springs in all of the safety valves in Unit I making all of them technically " inoperable."
In order for the valves to be declared operable, they must be tested for proner setpoint while at opefating temperature and pressure.
The previous specification did not allow entering Mode 3 and remaining in Mode 3 long enough to successfully test all of the valves. The proposed change to Table 3.7-1 would allow up to five main steam line safety valves to be inoperable if the reactor is restricted to no greater than Mode 3.
In Mode 3 the reactor may attain operating temperature and pressure but must be subcritical.
8611030509 861028 i
PDR ADOCK 05000413 p
. The " operability" of the main steam line safety valves ensures that the second-ary system pressure will be limited to within 110% (1304 psig) of its design pressure of 1185 psig during the most severe anticipated system operational transient. Since all the safety valves are considered inoperable before they are properly set, other means of secondary system overpressure protection have been provided while the reactor is in Mode 3.
The normal means of heat removal and pressure regulation is the steam dump to the condenser.
The steam dump is backed up by the automatic opening of the steam line PORVs on high pressure.
The automatic controls for the PORVs are not safety grade however the operators were instructed to manually open them if necessary to prevent secondary system overpressure. The manual controls for the PORVs are safety grade and are located in the control room. Because of the low rate of heat addition, ample time would be available to the operator to open the PORVs if required to prevent the maximum allowable secondary system pressure of 1304 psig from being exceeded.
In addi-tion, the licensee will reduce the power range monitor neutron flux high setpoint trip to 2% of r6ted thermal power. This provides dive nity to the source range monitor trip. Athough as orignally. requested, the high setpoint would have been zero, as oppostd to 2%, this change was necessitated in order to allow withdrawal of some of the control rods (part'of Mode 3-1.e., subtritical-operation).
Thus, this change does not affect the requirement for Mode 3 that the reactor must remain suberitical. The 2% trip setpoint is adequate because it is well below the 25% trip setpoint of the intennediate range neutron flux monitor and well above the 0% trip setpoint to avo M instrument drift.
This is consistent with the restriction that the reacte-st remain subcritical.
Based on the above discussion, the staff concludes that the proposed change tc Table 3.7-1 is not detrimental to the health and safety of the public and is, therefore, acceptable.
ENVIRONMENTAL CONSIDERATION The amendments involve a change in 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 m y be released offsite and that there is no significant increase in individual or cumulative occupational exposures.
The Commission has previously issued a proposed finding that the amendments involve no significant hazards consideration, and there have been no public comments on such finding. Accordingly, the amendments meet the eligibility criteric for categorical exclusion set forth in 10 CFR Section 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 amendments.
CONCLUSION The Commission made a proposed detennination that the amendments involve no significant hazards consideration which was published in the Federal Register (51 FR 32266) on September 10, 1986, and consulted with the State of South Carolina. No public comments were received, and the state of South Carolina did not have any comments.
f 7
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 corrpliance with the Cennission's regulations and the issuance of the amendments will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributors: Kahtan Jabbour, PWR#4/DPWR-A Walton Jensen, RSB/DPWR-A Dated: October 28, 1986 8O O
e
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _. _ _ _ _... _. _ _