ML20206D933
| ML20206D933 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 11/14/1988 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20206D931 | List: |
| References | |
| NUDOCS 8811170329 | |
| Download: ML20206D933 (2) | |
Text
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[o cut 'o UNITED STATES g
8 NUCLEAR REGULATORY COMMISSION o
h WA LHINGToN. D. C. 20556
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO.116 TO PROVISIONAL OPERATING LICENSE NO. OPR-20 CONSlHERS POWER COMPANY PALISADES PLANT DOCKET NO. 50-255 i
INTRODUCTION By letter dated August 4,1988, as supplemented October 4,1988, Consumers Power Company (tho licensee) requested amendment to the Technical Specifi-cations appendee to Provisional Operating License No. DFR-20 for the Palisades Plant.
The proposed amendment would reflect a change in the setpoint tolerances of the secondary system safety valves.
The change implements a 13% tolerance which is in accordance with the 1986 ASME Boiler 2
and Pressure Vessel Code, Sect,f on XI, IW-3500 and ANSI /ASME, OH-1-1981.
This tolerance is aise reflected in Advance Nuclear Fuels Corporation report ANF-87-150(NP) submitted to NRC by Consumers Power Company letter of June 17, 1988, to support Palisades operation with the modified reactor protection system and up to 29.3% steam generator tube p' gging.
Volume 2 of the report, Section 15.2.1, analyzes the results of th loss of load (trip of the turbine generator), which results in the greatest cua11enge to the safety valves, and concludes that the applicable acceptance criteria for the event are met.
No change to the surveillance method, interval, or criteria for expanding the sample size was requested.
The new 23% (or 130 psig) tolerance is less likely to result in additional valves beyond the typical 1/3 sample being tested each refueling outage.
The licensee provided additional information by letter on October 4, 1988, in which they committed to adjust the safety valves' setpoints to within 11% tolerance as necessary after testing.
EVALUATION The Code of Federal Regulations, 10 CFR 50.55a, requires, in part, that certain safety valves be tested in accordance with the ASME Section XI t
requirements.
The Palisades Inservice Testing (IST) program is based on the raquirements of Section XI of the ASME Code, 1983 Edition through the Summer of 1983 Addenda.
Section XI, IW-3512, in turn requires that safety valve and relief valve setpoints shall be tested in accordance#with ASME PTC 25.3-1976.
Section XI, IW-3513 and IW-3514, further require that when any valve in a system fails to function properly during a regular l
test, additional valves in the system shall be tested, and a valve failing to function properly during test shall be repair.!d or replaced.
The formula for determining the additional valves, contained in the licensee's August 4, 1988 letter and progedures, is consistent with the guideline provided in the 1983 ASME Code.
However, neither the 1983 Section XI nor r
PTC 25.3-1976 provide any requirements or guidelines for establishing valve l
1 K
P
2 s tpoint tolerance which would permit a reasonable deviation from the stamped set pressure due to valve setpoint drifting.
This issue was addressed in the 1986 ASME Section XI, IWV-3500, that endorsed the set pressure criteria provided in the ANSI /ASME, OM-1-1981.
0M-1-1981, states, in part, "Any valve exceeding its stamped set pressure by 3% or greater shall be repaired or replaced...."
It also provides a guideline for testing additional valves when a valve exceeds the 13% tolerance limits.
The 13% setpoint tolerance for the secondary safety valves was utilized in the ANF-87-150(NP) analysis.
For the three cases analyzed, the analysis demonstrates the adequacy of the relief valves in limiting steam pressure to 100 psig less than design.
Cases analyzed with the atmospheric dump valves and turbine bypass valves available did not challenge the safety valves.
The new minimum setpoint permitted by this change does not impact any analyzed events.
ANF-87-150(NP),
Section 15.1.3, analyzes two cases for excess load where the rapid opening of the atmospheric dump valves and turbine bypass valves exceed the steam flow rate which would result from the spurious opening of a safety valve The licensee's commitment to expand the scope of testing ff the 11% setpoint tolerance is exceeded and restore the valve to within 11% when a valve exceeds a 11% tolerance provides additional assurance of continuing valve operability.
ENVIRONMENTAL CONSIDERATION This amendment involves a change in the installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20. We have 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 this amendment involves no significant hazards consideration and there has been no public comment on such finding.
Accordingly, this 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 this amendment.
CONCLUSION 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 'n the proposed manner, and (2) such activities will be conductedincompliancewiththeCommission'sregulations,and)heissuanceof the amendment will not be inimical to the common defense and security or to the I
health and safety of the public.
Date:
November 14, 1988 Principal Contributors:
Yueh-Li C. Li Eric R. Swanson Thomas V. Wambach l
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