ML17223B265
| ML17223B265 | |
| Person / Time | |
|---|---|
| Site: | Saint Lucie  |
| Issue date: | 09/16/1991 |
| From: | Norris J Office of Nuclear Reactor Regulation |
| To: | Goldberg J FLORIDA POWER & LIGHT CO. |
| References | |
| IEB-88-008, IEB-88-8, TAC-69691, TAC-69692, NUDOCS 9109230218 | |
| Download: ML17223B265 (8) | |
Text
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~'eptember 16, 1991 Docket Nos.
50-335 and 50-389 Mr. J.
H. Goldberg President - Nuclear Division Florida Power and Light Company Post Office Box 14000 Juno Beach, Florida 33408-0420
Dear Mr. Goldberg:
DISTRIBUTION sa NRC 8 Local PDRs ACRS (10)
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SUBJECT:
ST.
LUCIE PLANT, UNITS 1
AND 2 -
NRC BULLETIN 88-08 "THERMAL STRESSES IN PIPING CONNECTED TO REACTOR COOLANT SYSTEMS" (TAC NOS.
69691 AND 69692)
By letter dated September 28, 1988, you responded to NRC Bulletin 88-08.
Your response stated that a review was performed of piping connected to the reactor coolant system (RCS).
The NRC staff and its consultant, Brookhaven National Laboratories, have completed the review of your response to Bulletin 88-08 and its supplements.
We have determined that your response is consistent with the modification or monitoring alternatives stated in the Bulletin.
Although no response was required related to Supplement 3 of the Bulletin, you are reminded that having been informed of the phenomenon identified in that supplement, you are responsible for adequate review of both its applicability to your plant and any considered actions.
'We may audit or inspect the implementation of Bulletin 88-08 and its supplements at a later date.
The enclosure contains information that you may use to assess the adequacy of your program with respect to Action 3 of the Bulletin, and Supplement 3.
Therefore, you meet the requirements of Bulletin 88-08 and no further action is required.
This completes our activity on TAC Nos.
69691 and 69692.
Sincerely,
/S/
Jan A. Norris, Sr. Project Manager Project Directorate II-2 Division of Reactor Projects - I/II Office of Nuclear Reactor Regulation
Enclosure:
As stated cc w/enclosure:
See next page DOC NAME:
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Mr. J.
H. Goldberg Florida Power 5 Light Company St. Lucie Plant cc Jack Shreve, Public Counsel Office of the Public Counsel c/o The Florida Legislature 111 West Madison Avenue, Room 812 Tallahassee, Florida 32399-1400 Senior Resident Inspector St. Lucie Plant U.S. Nuclear Regulatory Commission 7585 S.
Hwy A1A Jensen
- Beach, Flor ida 33457 Mr. Gordon Guthrie, Director Emergency Management Department of Community Affairs 2740 Centerview Drive Tallahassee, Florida 32399-2100 Harold F. Reis, Esq.
Newman 5 Holtzinger 1615 L Street, N.W.
Washington, DC 20036 John T. Butler, Esq.
- Steel, Hector and Davis 4000 Southeast Financial Center Miami, Florida 33131-2398 Administrator Department of Environmental Regulation Power Plant Siting Section State of Florida 2600 Blair Stone Road Tallahassee, Florida 32301 Mr. James V. Chisholm, County Administrator St. Lucie County 2300 Virginia Avenue Fort Pierce, Florida 34982 Mr. Charles B. Brinkman, Manager Washington Nuclear Operations ABB Combustion Engineering, Inc.
12300 Twinbrook Parkway, Suite 330 Rockvi 1 le, Maryland 20852 Mr. Jacob Daniel Nash Office of Radiation Control Department of Health and Rehabi litative Services 1317 Winewood Blvd.
Tal 1 ahassee, Flor ida 32399-0700 Regional Administrator, Region II U.S. Nuclear Regulatory Commission 101 Marietta Street N.W., Suite 2900 Atlanta, Georgia 30323 Mr. R.
E. Grazio Director, Nuclear Licensing Florida Power and Light Company P.O.
Box 14000 Juno Beach, Florida 33408-0420
N
Enclosure ST.
LUCIE UNITS I AND 2 EVALU TIO CRI RIA F R RESPONSES TO NRC B
TIN 88-8 ACTI N 3 AND S PPLEHENT 3
- 1. 0 OBJECTIVE To provide continuing assurance for the life of the plant that unisolable sections of reactor coolant system (RCS) will not be subjected to stratification and thermal cycling that cause fatigue failure of the piping.
2.0 PURPOSE 1.
To provide guidelines for evaluation of licensee responses.
2.
To provide acceptable procedures and criteria for preventing crack initiation in susceptible unisolable piping.
3.0 IDENTIFICATION OF POTENTIALLY SUSCEPTIBLE PIPING A.
Sections of injection piping systems, regardless of pipe size, which are normally stagnant and have the following characteristics:
1.
The source pressure is norma'1ly higher than the reactor coolant loop (RCL) pressure.
2.
Contain long horizontal runs.
3.
Are isolated by one or more check valves and a closed isolation valve in series.
4.
For sections connected to the RCL:
a.
Water injection is top or side entry.
b.
The first upstream check valve is located less than 25 pipe diameters from the RCL nozzle.
B.
Examples of such sections in PWRs are the safety injection lines and char ging lines between the RCL and the first upstream check valve, and the auxiliary pressurizer spray line between the charging line and the main pressurizer spray line.
Sections of other piping systems connected to the RCL, regardless of pipe size, which are normally stagnant and have the following characteristics:
1.
The downstream pressure is normally lower than RCL pressure.
2.
Are isolated by a closed isolation valve, or a check valve in series with a closed isolation valve.
3.
There is a potential for external leakage from the isolation valve.
Examples of piping containing such unisolable sections in PlJRs are the residual heat removal (RHR) lines.
Examples of such piping for BWRs are the RHR lines and the core spray injection lines.
4.0 ACCEPTABLE ACTIONS The following actions are considered as acceptable responses to Bulletin 88-08, Action 3 and Supplement 3,
as applicable, provided that the requirements of Bulletin 88-08, Action 2 have been satisfied.
1.
Revision of system operating conditions to reduce the pressure of the source upstream of the isolation valve below the RCL pressure during normal operation.
2.
Relocation of the check valves closest to the RCL to be at a distance greater than 25 pipe diameters from the nozzle.
3.
Installation of temperature monitoring instrumentation for valve leakage detection.
A.
Section of locations.
a.
Temperature monitoring should be performed by installing resistance temperature detectors (RTDs).
b.
RTDs should be located between first e'Ibow (elbow closest to the RCL), and the first check valve (check valve closest to the RCL).
c.
For the auxiliary pressurizer spray line, RTDs should be installed close to the "tee" connection to the main pressurizer spray line or in the cold portion (ambient temperature) of the line.
d.
RTDs should be located within six inches from the welds.
e.
At each location a
RTD should be positioned on top and bottom of the pipe cross-section.
B.
Determination of baseline temperature histories.
After RTD installation, temperature should be recorded during normal plant operation at every location over a period of 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.
The resulting temperature time-histories represent the baseline histories at these locations subject to the following conditions:
a.
The maximum top-to-bottom temperature difference should not exceed 50'F.
b.
Top and bottom temperature time-histories should be in-phase and not fluctuate by more than a30'f.
c.
If top-to-bottom temperature becomes out-of-phase, the bottom temperature should not fluctuate by more than 50'F.
C.
Section of monitoring time intervals.
a.
Monitoring should be performed at the following times:
l.
At the beginning of Mode 1 operation, after startup from a refueling shutdown 2.
At least a six-month intervals between refueling outages b.
During each monitoring period temperature readings should be recorded continuously for a 24-hour period.
c.
Temperature histories should correspond to the initially recorded baseline histories.
4.
Installation of pressure monitoring instrumentation for leakage detection.
A.
Selection of locations.
a.
Pressure monitoring should be performed by installing pressure transducers.
b.
Pressure transducer should be installed upstream and downstream of the first check valve.
B.,
Selection of monitoring time intervals.
a.
Monitoring should be performed at the following times:
1.
At the beginning of Mode I operation, after startup from a refueling shutdown 2.
At least at 6-month intervals, thereafter between refueling outages b.
Pressure readings should be recorded continuously for a 24-hour period.
c.
Pressure fluctuation criteria.
No limits on pressure fluctuations are specified.
The only requirement is that the downstream pressure (RCL pressure) should be greater than the upstream pressure at all times.
NOTES:
1.
Pressure transducers could also be installed across the first closed isolation valve of injection piping in which case the downstream pressure (the pressure in the pipe segment between the isolation valve and the check valve) should be lower than the upstream pressure.
An equalization of pressure indicates leakage through the valve seat and evertual "heck valve cycling.
2.
Pressure monitoring is not recommended, since pressure measurements may not provide an accurate indication of events in the unisolable pipe sections.
5.0 CORRECTIVE ACTIONS Corrective actions must be taken if the following conditions arise:
a.
Top-to-bottom temperature differences exceed 50'F.
b.
Top and bottom temperature time-histories become significantly out of phases.
c.
8ottom temperature oscillations exceed 50'F peak-to-peak.
d.
External leakage is detected in closed isolation valves.