ML20205P834
| ML20205P834 | |
| Person / Time | |
|---|---|
| Site: | Fort Saint Vrain  |
| Issue date: | 05/14/1986 |
| From: | Walker R PUBLIC SERVICE CO. OF COLORADO |
| To: | Gagliardo J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| References | |
| IEB-85-003, IEB-85-3, P-86356, NUDOCS 8605220097 | |
| Download: ML20205P834 (9) | |
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Or7cIso201owo oen R. F. WALKER PRESIDENT May 14, 1986 Fort St. Vrain Unit No. 1 P-86356 Rer;ional Administrator Reginn TV-U.S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 1000 Arlington, Texas 76011 Attn: Mr. J. G. Gagliardo, Chief Reactor Projects Branch Docket No. 50-267
SUBJECT:
Response to IE Bulletin 85-03
REFERENCE:
IE Bulletin 85-03 dated November 15, 1985 (G-85471)
Dear Mr. Gagliardo:
This letter provides PSC's response to IE Bulletin 85-03, Motor-Operated Valve Common Mode Failures During Plant Transients Due to Improper Switch Settings, as applicable to Fort St. Vrain.
The motor operated valves that are included in PSC's IE Bulletin 85-03 program are identified in Attachment 1,
along with their applicable design bases.
The additional information that is requestr.J by the Bulletin, such as test differential pressures and "as-found" and final switch settings, will be provided with PSC's final report upon completion of the program.
The scope of IE Bulletin 85-03 is specifically limited to motor operated valves in the high pressure coolant injection / core spray and emergency feedwater systems at a Light Water Reactor (LWR).
PSC considers that, for the purposes of the Bulletin and as discussed in Attachment 2,
the FSV emergency feedwater and emergency condensate systems are analogous to the aforementioned LWR systems.
This is based on a review of safe shutdown cooling systems at FSV, and is consistent with the review conducted as a part of the Technical Specification Upgrade Program, to determine which LWR Standard 3
Technical Specification systems are analogous to FSV systems, g\\
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P-86356 May 14, 1986
, includes PSC's program and schedule for ensuring that switch settings allow proper valve operation under maximum expected differential pressures, during both normal and abnormal events.
If you have any questions concerning this response, please contact Mr. M. H. Holmes at (303) 480-6960.
Very truly yours, S.NCUclAhu-R. F. Walker President cc:
U. S. Nuclear Regulatory Commission Document Control Desk Washington, D. C.
20555
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RFW/SWC/ljb Attachments
UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION In the Matter
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Public Service Company of Colorado
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Docket No. 50-267 Fort St. Vrain Unit No. 1
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AFFIDAVIT R. F. Walker, being first duly sworn, deposes and says that he is President of Public Service Company of Colorado, the Licensee herein, that he has read the foregoing report and knows the contents thereof, and that the statements and matters set forth therein are true and correct to the best of his knowledge, information and belief.
h.N. YcLAdM" R. F. Walker President h/fdIl
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STATE OF COUNTY OF IfMug/
Subscrig and sworn to before me, a Notary Public on this l4' - day of Y}') Ra,
, 1986.
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No y Public pgF My commission expires hur/zAd*,M,1988 d
ATTACHMENT 1 to P-86356 IE Bulletin 85-03 Motor Operated Valve Data Design Basis Valve Valve Operator Valve Function delta P (psi)
_0 pen /Close HV 3108, Limitorque, IA,18,1C Boiler 4500/4500 HV 3109, Model SMB-4T, Feed Pump Discharge HV 3110, Motor Speed Isolation 10" stop is 1705 rpm
- check, 2500 lb, Rockwell Edward HV 31118, Limitorque, IA, 1B, 1C Boiler 4500/4500 HV 31119, Model SMB-3, Feed Pump /
HV 31120, Motor Speed Emergency Feed 8" stop is 1720 rpm Header Isolation
- check, 2500 lb, Rockwell Edward HV 31208 Limitorque IB Boiler Feed 4500/4500 4" Globe, SMB-1 Pump Discharge 2500 lb, Motor Speed Bypass Rockwell is 1700 rpm Edward HV 31191, Limitorque, Emergency Condensate /
366/366 8" Gate Model SMB-0, Emergency Condensate
- Valve, Motor Speed Header Isolation 300 lb, is 1700 rpm Walworth HV 2237 Limitorque, Emergency Condensate /
366/366 HV 2238, Model SMB-4T, EES Header Isolation 8" Globe-Y, Motor Speed Loop 1, Loop 2 2500 lb, is 1685 rpm Rockwell 4
L.
Attachment.1 to P-86356 (Continued)
HV 2290
- Rotork, Emergency Condensa'e/
366/366 t
HV 2291, Type 70A, Reheater Isolation 6" Globe, Output Speed Loop 1, Loop 2 900 lb,
_.is 29 rpm Velan HV 3133-1, limitorque, Condensate Pump 366/366 HV 3135-1 Model SMB-0, Discharge Isolation 8" Gate, Motor Speed 300,1b, is 1700 rpm Walworth HV 3133-2 Limitorque, Condensate Pump /
366/366 HV 3135-2 Model SMB-00, Emergency Condensate 6" Gate, Motor Speed Header Isolation 300 lb, is 1700 rpm Walworth i:
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J ATTACHMENT 2 to P-86356 IE Bulletin 85-03 Determination of Applicable FSV Systems The scope of IE Bulletin 85-03 includes the high pressure coolant injection / core spray (HPCI/CS) and emergency feedwater systems.
HPCI/CS is the highest pressure injection system at an LWR, and is intended to provide the first line of defense to assure core cooling.
Emergency feedwater assures secondary heat removal.
Safe shutdown at Fort St. Vrain (FSV), a High Temperature Gas Cooled Reactor, is assured by providing diverse means of forced circulation and decay heat removal. The review of motor operated valves for IEB 85-03 includes the systems that assure safe shutdown and that have the highest operating pressure.
Primary coolant flow at FSV is normally provided by four steam driven helium circulators.
In the event that steam is not available, each helium circulator can be driven by a pelton wheel, supplied with emergency feedwater, emergency condensate, or firewater.
Of these, emergency feedwater has the highest operating pressure, 3620 psia.
At FSV, emergency feedwater is supplied by the same feedwater pumps that are in normal use, through a separate piping header.
Emergency condensate is also available, at a maximum operating pressure of 366 psia.
Decay heat removal is assured by providing (emergency feedwater through ~the economizer-evaporator-superheater EES) sections of either of two steam generators, or by supplying emergency condensate or firewater through either the EES or reheater sections of either steam generator.
For the purpose of defining the scope of the IEB 85-03 program for motor operated valves at Fort St. Vrain, PSC considers that the emergency feedwater and emergency condensate systems are analogous tc the HPCI/CS and emergency feedwater systems at an LWR.
a.
Emergency feedwater is included because it is the highest pressure system that assures core cooling.
It provides motive power for forced circulation and it removes decay heat through the steam generators.
Emergency feedwater valves included in the IEB 85-03 program are those that assure a flowpath from the boiler feed pumps.
- to P-86356 (Continued) b.
Emergency condensate is included because it is FSV's second line of defense to assure core cooling, and it uses equipment that is independent of the emergency feedwater system.
Emergency condensate valves included in the IEB 85-03 program are those that assure a flowpath to the steam generators. No other motor operated valves are relied upon to supply emergency condensate to the helium circulator drives.
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ATTACHMENT 3 to P-86356 Program for Motor Operated Valve Switch Settings 1.
PSC is currently in the process of developing a program which will ensure that motor operated valves (M0Vs) will function properly, under all differential pressures that are expected during normal and abnormal operations.
PSC has contacted several vendors who either have developed, or are in the process of developing, test programs for M0V switch settings.
2.
M0V test methodologies being considered generally include the following:
a.
A test device is mounted on the valve, and a force is then applied to the valve stem, simulating a service differential pressure.
The switches are then adjusted to allow proper valve operation. Switches will be set to allow for the higher torques required for operation against high operating differential pressures, and to eliminate damaging overtravel.
b.
During the service simulation, motor current and voltage parameters are monitored.
A functional relationship is developed that will allow operator performance to be subsequently verified regardless of the pressure in the valve.
c.
Operator performance can then be verified by comparing operating parameters with the funct.ional relationship developed above.
This verification will be performed at least once per 18 months, and after valve or operator maintenance.
3.
PSC plans to validate the test methodology by operating the valve with maximum practical differential pressures across the seat.
This validation will be performed once, for each motor operator size and manufacturer, on a valve with the highest expected service differential pressure.
4.
PSC's current schedule for the motor operated valve program is as follows:
a.
By the end of 1986, a test method and vendor will be selected.
b.
By November 15, 1987, the valve switch settings will be established, the switches will be calibra tdl, and satisfactory valve operation will be demonstrated.# At this time, correct switch settings will be incorporated into plant procedures.
' Attachment.3 to P-86356 (Continued)
This valve testing must be performed during a plant outage, an.d in the event that refueling outage scheduling would extend beyond November 15, 1987, PSC will notify the NRC and request approval for any required extensions.
c.
As required by the Bulletin, a written report will be submitted within 60 days of completion of the above program.