ML17056B524
| ML17056B524 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 10/10/1991 |
| From: | Brinkman D Office of Nuclear Reactor Regulation |
| To: | Sylvia B NIAGARA MOHAWK POWER CORP. |
| References | |
| IEB-88-008, IEB-88-8, TAC-M69655, NUDOCS 9111250253 | |
| Download: ML17056B524 (14) | |
Text
Docket No. 50-220 Hr. B. Ralph Sylvia Executive Vice President, Nuclear Niagara Mohawk Power Corporation 301 Plainfield Road
- Syracuse, New York 13212
Dear Mr. Sylvia:
,DISTRIBUTION:
NRC 8 Local PDRS PDI-I Readings S.
Varga J.
Calvo R. A. Capra D. Brinkman C.
Vogan October 10, 1991 B. Mozafar i OGC E. Jordan ACRS (10)
Plant File C. Cowgill H. Hartzman J.
Norberg
SUBJECT:
RESPONSE
BY NINE MILE POINT NUCLEAR STATION UNIT NO.
1 TO NRC BULLETIN 88-08 AND SUPPLEMENTS (TAC NO.J)69655)
By letter dated September 29, 1988, Niagara Mohawk Power Corporation (NMPC) responded to NRC Bulletin 88-08 and Supplements I and 2.
In its response, NMPC identified piping systems which may be susceptible to the thermal cycling phenomena described in the bulletin.
Based on our review of your response, we have concluded that NMPC has satisfied the reporting requirements of Action I of the bulletin.
However, with regard to Action 2 of the bulletin, your response is incomplete and a supplemental response to confirm completion of the required examinations should be submitted.
We also noted that your response did not provide justification for not responding to Action 3 of the bulletin, as applicable, for portions of the Emergency Cooling System and the Feedwater System.
Therefore, we request that you supplement your response to these items requested by the bulletin.
Please provide the requested information within 60 days of receipt of this letter.
The enclosure to this letter contains criteria and guidelines that you may utilize in developing and implementing a program in response to Action 3 of the bulletin.
Your response should describe NMPC's implementation of this program.
Please note that Inservice Inspection was not identified as an option for satisfying the requirements of Action 3 of the bulletin.
The requirements of this letter affect fewer than 10 respondents
- and, therefore, are not subject to Office of Management and Budget review under P.L.96-511.
Enclosure:
As stated S incere ly, ORIGINAL SIGNED BY:
Donald S. Brinkman, Senior Project Manager Project Directorate I-I Division of Reactor Projects - I/II Office of Nuclear Reactor Regulation cc w/enclosure:
See next page
- CVogan
~ W W DATE: / " /91 WO AW
- DBrinkman:amm WWWWW
~
~
- Ic / t/91 0
- RACapra A
~
~ WO W
~
~
J> //0/91
~
ocumen arne:
91ii250253 9iiOf0 PDR ADOCK 05000220 PDR
~
1" fl ltb 1 r
I
,I P
~ r fn I 'br
~
nil nf'n 'f 'P'
~ Q
y
~
II Ill I
h
~ n Efb I I r
'I f'P I ln If ~
n I'
h l
fb I,~ hfh 1 II 1'bff 1
1 rbnh p
~
b
~ n b.1 1
b
'f l P b
r 1 ~ Ph h b h ffhl rb 'p I lb f,nl I
lh fl nbhh
>>'b')
1 fb ~
1 hl 1
p(r, ~
I h ( I f' h
phprnn1',
nb Pl I
Pl K If Ff'"
Ib
)
'I >> lib h
~
)I nnnf% I 1
h'grll ~
~
rp rn b
1, II f
'I In" bn 1
q r
~
1 11 I
Pf
gpss RECT(
0
~a~))W -w
()i
+**<<+
Docket No. 50-220 UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555 October 10, 1991 Mr. B. Ralph Sylvia Executive Vice President, Nuclear Niagara Mohawk Power Corporation 301 P la infiel d Road
- Syracuse, New York 13212
Dear Hr. Sylvia:
SUBJECT:
RESPONSE
BY NINE HILE POINT NUCLEAR STATION UNIT NO. I TO NRC BULLETIN 88-08 AND SUPPLEMENTS (TAC NO. 69655)
By letter dated September 29, 1988, Niagara Mohawk Power Corporation (NHPC) responded to NRC Bulletin 88-08 and Supplements I and 2.
In its response, NMPC identified piping systems which may be susceptible to the thermal cycling phenomena. described in the bulletin.
Based on our review of your response, we have concluded that NHPC has satisfied the reporting requirements. of Action I of the bulletin.
However, with regard to Action 2 of the bulletin, your response is incomplete and a supplemental response to confirm completion of the required examinations should be submitted.
We also noted that your response did not provide,justification for not responding to Action 3 of the bulletin, as applicable, for portions of the Emergency Cooling System and the Feedwater System.
Therefore, we request that you supplement your response to these items requested by the bulletin.
Please provide the requested information within 60 days of receipt of this letter.
The enclosure to this letter contains criteria and guidelines that you may utilize in developing and implementing a program in response to Action 3 of the bulletin.
Your response should describe NHPC's implementation of this program.
Please note that Inservice Inspection was not identified as an option for satisfying the requirements of Action 3 of the bulletin.
The requirements of this letter affect fewer than 10 respondents
- and, therefore, are not subject to Office of Management and Budget review under P.L.96-511.
S incerely,
Enclosure:
As stated Donald S. Brinkman, Senior Project Manager Project Directorate I-1 Division of Reactor Projects - I/II Office of Nuclear Reactor Regulation cc w/enclosure:
See next page
~ r
Mr. B. Ralph Sylvia Niagara Mohawk Power Corporation Nine Mile Point Nuclear Station Unit No.
1 CC:
Hr. Hark J. Wetterhahn, Esquire Winston 5 Strawn 1400 L Street, NW.
Washington, D.C.
20005-3502 Yr. Kim Dahlberg Unit 1 Station Superintendent Nine Mile Point Nuclear Station Post Office Box 32
- Lycoming, New York 13093 Supervisor Town of Scriba Route 8, Box 382
- Oswego, New York 13126 Mr. Joseph F. Firlit Vice President - Nuclear Generation Niagara Hohawk Power Corporation Nine Mile Point Nuclear Station Post Office Box 32
- Lycoming, New York 13093 Resident Inspector U.S. Nuclear Regulatory Commission Post Office Box 126
- Lycoming, New York 13093 Mr. Gary D. Wilson, Esquire Niagara Mohawk Power Corporation 300 Erie Boulevard West
- Syracuse, New York 13202 Regional Administrator, Region I U.S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, Pennsylvania 19406 Hs.
Donna Ross New York State Energy Office 2 Empire State Plaza 16th Floor
- Albany, New York 12223 Hr. David K. Greene Manager Licensing Niagara Mohawk Power Corporation 301 Plainfield Road
- Syracuse, New Yor k 13212 Charlie Donaldson, Esquire Assistant Attorney General New York Department of Law 120 Broadway New York, New York 10271 Mr. Paul D.
Eddy State of New York Department of Public Service Power Division, System Operations 3 Empire State Plaza
- Albany, New York 12223
Enclosure CRITERIA AND GUIDELINES FOR DEVELOPING AND IMPLEMENTING 7TH 8768 lETTM 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 (I)
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 more check valves and a closed isolation valve in series.
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
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 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 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 histories are out-of-phase and the bottom peak-to-peak temperature fluctuations exceed 50'F.
d.
Temperature histories do not correspond to the initially recorded baseline histories.
e ~
(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 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:
a ~
b.
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.
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.
I U
1