ML17262A944
| ML17262A944 | |
| Person / Time | |
|---|---|
| Site: | Ginna  |
| Issue date: | 08/06/1992 |
| From: | Andrea Johnson Office of Nuclear Reactor Regulation |
| To: | Mecredy R ROCHESTER GAS & ELECTRIC CORP. |
| References | |
| IEB-88-008, IEB-88-8, TAC-M69633, NUDOCS 9208130159 | |
| Download: ML17262A944 (14) | |
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CLEAR REGULATORY CQtNVIl ~~-'II i WASHINGTON, D. C. 20555 August 6, 1992 Docket No. 50-244 Dr. Robert C. Hecredy, Vice President Ginna Nuclear Production Rochester Gas 5 Electric Corporation 89 East Avenue Rochester, New York 14649
Dear Dr. Hecredy:
SUBJECT:
NRC BULLETIN 88-08 "THERHAL STRESSES IN PIPING CONNECTED TO REACTOR COOLAN'f SYSTEHS" (TAC NO. H69633)
By letters dated September 28,
- 1988, and June 22,
- 1989, Rochester Gas and Electric Corporation (RGEE) 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 it supplements.
The staff has determined that your response is consistent with modification or monitoring alternatives stated in the Bulletin.
Although no response was requfred related to Supplement 3 of the Bulletin, some licensees have addressed Supplement 3 in their response to the Bulletin.
Those who have not will not be required to provide a specific response to Supplement 3.
According to our records RGKE did not voluntarily respond to Supplement 3.
- However, 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.
NRC staff 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.
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Dr. Robert C. Hecredy August 6, 1992 Therefore, you meet the requirements of Bulletin 88-08 and no further action is required.
This completes our activity on TAC number H69633.
Sincerely, Original signed by Allen R. Johnson, Project Manager Project Directorate I-3 Division of Reactor Projects - I/II Office of Nuclear Reactor Regulation
Enclosure:
As stated cc w/enclosure:
See next page DISTRIBUTION:
', Docket File No. 50-244 NRC
& Local PDRs PDI-3 reading file S.
Varga G. Lainas W. Lazarus, RI H. Rushbrook A. Johnson J.
Calvo B. Hozafari E.
Adensam T.
Chan OGC (info. only)
ACRS (10)
J. Linville, RI R.
Lobel OFFICE NANE DATE PDI-HRush roo PDI-3/PH AJohnson:mw 92 PDI-D e ses
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/92 OFFICIAL RECORD COPY DOCUMENT NAME: GIM69633.LTR
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Dr. Robert C. Hecredy Ginna CC:
Thomas A. Moslak, Senior Resident Inspector R.E.
Ginna Plant U.S. Nuclear Regulatory Commission 1503 Lake Road
- Ontario, New York 14519 Regional Administrator, Region I U.S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, Pennsylvania 19406 Hs.
Donna Ross Division of Policy Analysis 8 Planning New York State Energy Office Agency Building 2 Empire State Plaza
- Albany, New York 12223 Charlie Donaldson,
- Esq, Assistant Attorney General New York Department of Law 120 Broadway New York, New York 10271 Nicholas S. Reynolds Winston
& Strawn
.1400 L St.
N.W.
Washington, DC 20005-3502 Ms. Thelma Wideman
- Director, Wayne County Emergency Management Office Wayne County Emergency Operations Center 7370 Route 31
- Lyons, New York 14489 Hs.
Mary Louise Heisenzahl Administrator, Monroe County Office of Emergency Preparedness.
111 West Fall Road-,
Room, ll Rochester, New York 14620
k 1
Encl osure EVALUATION CRITERIA FOR RESPONSES TO NRC BULLETIN 88-08 ACTION 3 AND SUPPLEMENT 3
- 1. 0 OBJECTIVE 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.
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The piping sections contain long horizontal runs.
C.
The piping systems are isolated by one or more check valves and a closed isolation valve in series.
D.
For sections connected to the RCS:
a.
Mater 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 mai vressurizer 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.
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"2-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).
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 - ipe 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
lh
hours.
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 504F.
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 operation, 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 60 F.
C.
Top and bottom temperature t...tories are out-of-phase and the bottom peak-to-peak temperature fluctuations exceed 500F.
d.
Temperature histories do not correspond to the initially'ecorded baseline histories.
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(4}
Installation of pressure monitoring instrumentation for leakage detection in injection lines.
(Pressure monitoring is not the preferred method since pressure measurements cannot provide a measurement of thermal cycling in the unisolable pipe sections.)
A.
Type and location of sensor s.
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:
1.
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:
aO 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.
0 A
C