ML20082P264
| ML20082P264 | |
| Person / Time | |
|---|---|
| Site: | Point Beach  |
| Issue date: | 09/05/1991 |
| From: | Fay C WISCONSIN ELECTRIC POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| CON-NRC-91-093 VPNPD-91-303, NUDOCS 9109100258 | |
| Download: ML20082P264 (5) | |
Text
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Wisconsin E!!sn:tnc l
- POWER COMPANY 231 W Michgan. PO Box 2046. Mhoutte WI 53201
[414)221 2345.
VPNPD-91-303 NRC 093 September'5, 1991-Document Control Desk U.
S.
NUCLEAR REGULATORY COMMISSION Mail Station P1-137 Washington, DC 20555 Gentlemen:-
DOCKETS 50-266 AND 50-301 SUPPLEMENT TO GENERIC LETTER 88-14 RESPONSES POINT BEACH NUCLEAR PLANT, UNITS 1 AND 2 In'a letter dated July 9,.1991, we stated that we had completed all items in our February 20, and July 27, 1989 letters that responded l
However, in Inspection Report 50-266/90020; 50-301/90020, dated January 16, 1991, the NRC staff
' determined that we had not fully. complied with the -tatements'in our February 20,- 1989 letter regarding testing of safety-related pneumatically operated valves (SRPOVs)..This letter is intended to clarify the actions that we have completed in-response to GL 88-14.
Additionally,Las committed to in our February 15, 1991 letter, this letter provides a report on the results of our crossover stear dump valve testing.
GL_88-14 requested that licensees review-NUREG-1275, Volume 2, and perform design and operations verifications to ensure that air-operated safety-related components in-SRPOVs will perform as expected in accordance with all design-basis events, lncluding a loss of the normal instrument air system.
Specifically, NUREG-1275, Volume 2, recommends that.the design verification should' include the rapid and gr adual Instrument Air. (IA) system bleed down tests that are described in Regulatory Juide (RG) s 1.68.3, "Preoperational Testing of Instrument and Control Air Systems."
These tests involve simulating a loss of instrument air.
to the largest practicable branch of the IA system to ensure that air operated components fail to their designed position.
Please note that these tests were not required in the original licensing i
basis-of our plant-and RG 1.68.3 was published well afcer the preoperationalitesting at Point Beach had been completed.
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Document Control Desk September 5, 1991 Page 2 In our February 20, 1989 letter we stated that "All safety-related pneumatic equipment at PBNP is designed to fail to a safe condition with the sSfety function being tested in the PBNP Inservice Test Program."
During NRC Inspection 90020, the inspector noted that the PBNP Inservice Test (IST) program did not provide the fail-safe design verification tests requested in GL 88-14.
Fail-safe testing in accordance with our IST program generally involves verifying that a SRPOV fails to its designed fail position when the normal operating switch is used to vent air pressure off of the valve's operator.
Although our IST program does not include the preoperational rapid or gradual bleed down testing t: hat is described in RG 1.68.3, our IST program does test the safety function of SRPOVs.
We do not plan to perform RG 1.68.3 testing on SRFOVs that are fail-safe tested in our IST program, since we have concluded that our current IST program provides adequate fail-safe verification.
Nonetheless, during the Fall of 1990, we randomly tested ten SRPOVs.
A pressur7 test rig was connected to individual SRPOVs and testing was performed by bleeding air off the SRPOV operators.
Separate tescs were conducted with the valves in the opened and closed positions for both rapid and gradual biced downs to ensure that the valves failed to the correct position in all cases.
In addition to the bleed down tests, an overpressurization test was conducted on each of the subject SP,POVs.
All of these special SRPOV tests were completed satisfactorily.
GL 88-14 also requested that we conduct tests to ensure that
" air-operated safety-related components will perform as expected in accordance with all design-basis events."
During NRC Inspection l
90020, the inspector noted that contrary to our February 00, 1989 letterProperty "Letter" (as page type) with input value "05000000/LER-1950-266-75, /75-18:on 751217,during Cycle 3-4 Refueling, Discovered Section of Fuel Rod Missing.Caused by Water Impingement Through Baffle Plate While Failed Assembly in Cycle 2 Position H-1.Investigation in Progress"February 00, 1989" contains a sequence that could not be interpreted against an available match matrix for date components." contains invalid characters or is incomplete and therefore can cause unexpected results during a query or annotation process., some of our SRPOVs were not tested in the IST program.
l The ASME Section XI (1986), " Inservice Testing of Valves in Nuclear l
Power Plants" requires fail safe testing for " active" valves, namely valves that must perform a mechanical motion during the course of accomplishing a system safety function. -The Point Beach IST program includes fail safe testing for " active" FRPOVs.
Safety related valves which are " passive," namely valves that do not perforan a mechanical motion during the course of accomnlishing a system safety function, are excluded from the IST reqr eements of ASMF Section XI (1986), and thus they are not fail-safe tested in our IST program.. SRPOVs that are currently not fail-safe tested in the IST program include:
t Document Control Desk
-l September 5, 1991 i
Page 3 i
1.
1-MS-02042 & 02045; 2-MS-02042 & 02045 - Steam Generator 1
Blowdown Isolation Valves
[
2.
1-CV-01296; 2-CV-01296 - Auxiliary Charging Containment t
Isolation Valves 3.
1-RH-00624 & 00625; 2-RH-00624 & 00625 - Residual Heat Removal-(RHR) Heat Exchanger Outlet Valves j
4.
1-RH-00626; 2-RH-00626 - RHR Heat Exchanger Bypass Valves 5.
1-SI-00825C; 2-SI-00825C - Safety Injection Pump Minimum i
Flow Suction From Refueling Water Storage Tank (MOV-825 A
&'B Bypass) Valves 6.
1-SI-00835A & B; 2-SI-00835A & B - SIS Accumulator Makeup Valves e
7.
1-SI-00839A, B.
C.
& D; 2-SI-00839A.
B.
C.
& D - Safety Injection Loop Cold Leg / Accumulator Test Valves 7
8, 1-SI-00844A & B; 2-SI-00844A & B - SIS Accumulator Drain
~
Valves 9.
1-RC-00431A & B; 2-RC-00431A & B - T-1 Pressurizer Spray Line Pressure Control Valves 10.
1-CV-00133; 2-CV-00133 - Residual Heat Removal (RHR) to Letdown Orifices Outlet Hand Control Valves With the exception of 1-CV-00133 and-2-CV-00133, all of the above listed valves are addressed in the PBNP IST Basis Document which includes explanations describing why individual valves have been i
excluded from the IST program.
In accordance with_ASME Section XI, Subsection IWV-1200, the RHR to letdown orifices. outlet hand L.
control valves (1-CV-00133 and 2-CV-00133), do not need to be included in the IST program because they are control valves that do
-not perform a specific function in shutting down a reactor or in i
mitigating the consequences of an accident.
L 3
Document Control Desk September 5, 1991 Page 4 The Point Beach IST Program is currently in its third 10 year interval.
The IST Program Document was revised and reissued in December 1990 when the third interval began.
As part of the third interval program revision, several SRPOVs were reevaluated and fail-safe testing was implemented into the IST program as necessary. -As a resu.t, the following SRPOVs, which were not included in the IST program in February 1989 when we responded to GL 88-14, are now incladed in the IST programt 1.
AF-04007; AF-Ot014; 1-AF-04002; 2-AF-04002 - Auxiliary Feedwater Mini-Recirc Valves (IST fail-safe testing implemented in December 1990) 2.
1-MS-02015 & 02016; 2-MS-02015 & 02016 - Steam Generator Atmospheric Steam Dump Control Valves (IST fail-safe testing implemented in December 1990) 3.
1-SI-0083*A & B; 2-SI-00834A & B - SIS Accumulator Vent Valves (IST fail-safe testing implemented in December 1990) 4.
1-SI-00957; 2-SI-00912 - SIS Accumulator Combined Vent Valves (IGT fail-safe testing implemented in December 1990) 5.
1-SC-00959; 2-SC-00919 - RHR Loop Sample Isolation Valves (IST fail-safe testing implemented in March 1990) l In summary, the statement in our February 20, 1989, letter which l
concluded that we test all safety related equipment in the IST program, was not accurate.
Since that time we have reevaluated a number of those valves and included their fail-safe tests in our IST program, as noted above.
Additionally, our IST program excludes valve testing on SRPOVs that we have determined will not perform mechanical motions during the coursa of accomplishing a system safety function.
We do not, however, intend to perform RG 1.68.3 testing on passive valves that we have determined are currently outside the scope of our IST program.
We believe the.
above actions properly address the concerns transmitted in i
our February 15, 1991, letter we committed to inform the NRC staff of the results of our crossover steam dump valve testing.
We tested the operation of the crossover steam dump pilot valves at various instrument air (IA) header pressures within the manufacturer's recommended operating range of 20 - 90 psi.
We determined that the pilot valves will operate reliably only when at
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c Document Control Desk
. September 5.
1991 Page 5 i
i t
r least 40 psi IA header pressure is applied.
We have taken into account these test results when establishing the pilot valve IA supply pressure setpoints within the manufacturer's recommended operating band.
We have installed an accumulator and check valve combination to ensure that adequate air pressure will be maintained to the pilot valve if the IA system pressure is lost.
We are also l
pursuing development of a design change to provide a more reliable fail-safe valve upon loss of IA system pressure.
I If you have any questions concerning this information, please p
contact us.
l Very truly yours,
(% L/,$1l C.
W.
Pby Vice Presi nt Nuclear Power i
Copy to:
NRC Resident Inspector l
NRC-Regional Administrator i
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