ML17348B127
| ML17348B127 | |
| Person / Time | |
|---|---|
| Site: | Turkey Point  |
| Issue date: | 09/23/1991 |
| From: | Rajender Auluck Office of Nuclear Reactor Regulation |
| To: | Goldberg J FLORIDA POWER & LIGHT CO. |
| References | |
| IEB-88-008, IEB-88-8, TAC-69700, TAC-69701, NUDOCS 9110040023 | |
| Download: ML17348B127 (9) | |
Text
~ eptember 23, 1
Docket Nos.
50-250 and 50-251 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 OGC HRC and Local PDRs ACRS(10)
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SUBJECT:
TURKEY POINT PLANT, UNITS 3 AND 4 -
HRC BULLETIN 88-08 "THERMAL STRESSES IN PIPING CONNECTED TO REACTOR COOLANT SYSTEMS" (TAC NOS.
69700 AND 69701)
By letter dated October 14, 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.
4 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.
69700 and 69701.
Sincerely, (Original Signed By)
G PDR
Enclosure:
As stated cc w/enclosure:
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BULLETIN 88-08 TURKEY POINT
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Nr. J.
H. Goldberg Florida Power and Light Company Turkey Point Plant CC:
Harold F. Reis, Esquire Newman and Holtzinger, P.C.
1615 L Street, N.W.
Washington, DC 20036 Jack Shreve, Public Counsel Office of the Public Counsel c/o The Florida Legislature ill West htadison
- Avenue, Room 812 Tallahassee, Florida 32399-1400 John T. Butler, Esquire
- Steel, Hector and Davis 4000 Southeast Financial Center l!i'ami, Florida 33131-2398 l<r. Thomas F. Plunkett, Site Vice President Turkey Point Nuclear Plant Florida Power and Light Company P.O.
Box 029100 Miami, Florida 33102 Joaquin Avino County Manager of ttetropo1 itan Dade County 111 NW 1st Street, 29th Floor tliami, Florida 33128 Senior Resident Inspector Turkey Point Nuclear Generating Station U.S. Nucle'ar Regulatory Commission Post Office Box 1448 Homestead, Florida 33090 fir. Jacob Daniel Nash Office of Radiation Control Department of Health and Rehabilitative Services 1317 Winewood Blvd.
Tallahassee, Florida 32399-0700 Nr. Gordon Guthrie, Director Emergency management Department of Community Affairs 2740 Centerview Drive Ta 1 1 ahassee, Florida 32399-2100 Administrator Department of Environmental Regulation Power Plant Siting Section State of Florida 2600 Blair Stone Road Tallahassee, Florida 32301 Regional Administrator, Region II U.S. Nuclear Regulatory Commission 101 llarietta Street, N.W. Suite 2900 Atlanta, Georgia 30323 Attorney General Department of Legal Affairs The Capitol Tallahassee, Florida 32304 Plant Hanager Turkey Point Nuclear Plant Florida Power and Light Company P.O.
Box 029100 Niami, Florida 33102 her.
R.
E. Grazio Director, Nuclear Licensing Florida Power and Light Company P.O.
Box 14000 Juno Beach, Florida 33408-0420
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Enclosure EVALUATION CRITERIA FOR RESPONSES TO NRC BULLETIN 88-08 ACTION 3 AND SUPPLEMENT 3
- 1. 0 OBJ ECTIVE To provide continuing assurance for the life of the plant that unisolable sections of piping connected to the reactor coolant system (RCS) will not be subjected to thermal stratification and thermal cycling that could cause fatigue failure of the piping.
2.0 PURPOSE To provide guidelines for evaluation of licensee responses, including acceptable procedures and criteria to prevent crack initiation in susceptible unisolable piping.
3.0 IDENTIFICATION OF POTENTIALLY SUSCEPTIBLE PIPING (1)
Sections of injection piping systems, regardless of pipe size, which are normally stagnant and have the following characteristics:
A.
The pressure is higher than the RCS pressure during reactor power operation.
B.
The piping sections contain long horizontal runs.
C.
The piping systems are isolated by one or'ore check valves and a closed isolation valve in series.
2 D.
For sections connected to the RCS:
a.
Water injection is top or side entry.
b.
The first upstream check valve is located less than 25 pipe diameters from the RCS nozzle.
Examples of such sections in PWRs are the safety injection 'lines and charging lines between the reactor coolant loop and the first upstream check valve, and the auxiliary pressurizer spray line between the charging line and the main pressurizer spray line.
(2)
Sections of other piping systems connected to the RCS, regardless of pipe size, which are normally stagnant and have the following characteristics:
A.
The downstream pressure is lower than RCS pressure during reactor power operation.
B.
The piping systems are isolated by a closed isolation valve, or a check valve in series with a closed isolation valve.
C.
There is a potential for external leakage from the isolation valve.
Examples of piping containing such unisolable sections in PWRs 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 water upstream of the isolation valve below the RCS pressure during power operation.
(2)
Relocation of the check valves closest to the RCS to be at a distance greater than 25 pipe diameters from the nozzle.
(3)
Installation of temperature monitoring instrumentation for detection of piping thermal cycling due to valve leakage.
A.
Type and location of sensors.
a.
Temperature sensors should preferably be resistance temperature detectors (RTDs).
b.
RTDs should be located between the first elbow (elbow closest to the RCS),
and the first check valve (check valve closest to the RCS).
C.
For the auxiliary pressurizer spray line, RTDs should be installed near the "tee" connection to the main pressurizer spray line or on the cold portion (ambient temperature) of the line.
d.
RTDs should be located within six inches of the welds.
e.
At each pipe cross section, one RTD should be positioned on the top of the pipe and another RTD on the bottom of the pipe.
B.
Determination of baseline temperature histories.
After RTD installation, temperature should be recorded during normal plant operation at every location over a period of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
The resulting temperature versus time records represent the baseline temperature histories at these locations.
Baseline temperature histories should meet the following criteria:
a.
The maximum top-to-bottom temperature difference should not exceed 50'F.
b.
Top and bottom temperature time histories should be in-phase.
c.
Peak-to-peak temperature fluctuations should not exceed 60 F.
C.
Monitoring time intervals.
a.
Monitoring should be performed at the following times:
l.
At the beginning of power oper ation, after startup from a refueling shutdown 2.
At least at six-month intervals thereafter, between refueling outages b.
During each monitoring period, temperature readings should be recorded continuously for a 24-hour period.
D.
Exceedance Criteria.
Actions should be taken to modify piping sections or to correct valve leakage if the following conditions occur:
a ~
The maximum temperature difference between the top and the bottom of the pipe exceeds 50'F.
b.
Top and bottom temperature histories are in-phase but the peak-to-peak fluctuations of the top or bottom temperatures exceed 604F.
C.
Top and bottom temperature histories are out-of-phase and the bottom peak-to-peak temperature fluctuations exceed 50 F.
Temperature histories do not correspond to the initially recorded baseline histories.
"4-(4)
Installation of pressure monitoring instrumentation for leakage detection in injection lines.
(Pressure monitoring is not the preferred method since pressure measur ements cannot provide a measurement of thermal cycling in the unisolable pipe sections.)
A.
Type and location of sensors.
a.
Pressure sensors should preferably be pressure transducers.
b.
Pressure transducers should be installed upstream and downstream of the first check valve.
C.
For systems having a pressure higher than the RCS pressure, pressure transducers may be installed upstream and down-stream of the first closed isolation valve.
(The downstream section is the pipe segment between the isolation valve and the check valve.)
B.
Monitoring time intervals.
a.
Monitoring should be performed at the following times:
l.
At the beginning of power operation, after startup from a refueling shutdown 2.
At least at six-month intervals thereafter, between refueling outages b,
Pressure readings should be recorded continuously for a 24-hour period.
C.
Exceedance criteria.
Actions should be taken to modify piping sections or to correct valve leakage if the following conditions occur:
For pressure measurements across a check valve, the downstream pressure (RCS pressure) is equal to or less than the upstream pressure at any time during power operation.
b.
For pressure measurements across a closed isolation valve, the downstream pressure is equal to or greater than the upstream pressure at any time during power operation.
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