ML19350C467
| ML19350C467 | |
| Person / Time | |
|---|---|
| Site: | Vermont Yankee File:NorthStar Vermont Yankee icon.png |
| Issue date: | 03/19/1981 |
| From: | Conway W VERMONT YANKEE NUCLEAR POWER CORP. |
| To: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| FVY-81-46, IEB-80-25, NUDOCS 8104030249 | |
| Download: ML19350C467 (3) | |
Text
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VERMONT YAN KEE NUCLEAR POWER CORPORATION SEVENTY SEVEN GROVE STREET RUTLAND, VERMONT 05701 2.C.2.9 REPLY TO:
ENGINEERING OFFICE 1671 WORCESTER ROAD FR AMINGH AM. M ASS ACH US ETTS O17of TELEPHoNa et7.e72 stoo United States Nuclear Regulatory Commission f ] jj p 0 0 i
Office of Inspection and Enforcement 12 9-J Jgg Region I 631 Park Avenue Q
'cer King of Prussia, Pennsylvania 19406 4
7 Attention:
Mr. Boyce Grier, Director 4
References:
(a)
License No. DPR-28 (docket No. 50-271)
(b)
Letter Boyce H. Grier.(USNRC) to R.L. Smith (VYNPC) dated December 19, 1980, IE Bulletin 80-25
Dear Sir:
Subject:
Response to.IE Bulletin 80-25, Operating Problems with Target Rock Safety Relief Valves at BWRs Reference (b) delineates certain actions to be taken by BWR li-censees and subsequent reporting requirements. The following infor-mation is submitted on behalf of Vermont Yankee.
Item 1 "If your facility has not yet installed or changed or is presently in the process of changing to the two-state S/R valves, initiate appropriate quality control procedures to assure inspection of the solenoid actuators for excess Loc-tite prior to operation.
If the solenoid actuator manufactured by Target Rock Corporation is already in-stalled in your facility, confirm its operability either by its operational performance (i.e., it.has functioned as designed following an aging period of about 3 months in the higher temperature environment of power operating conditions) or by functional testing at full pressure during the next refueling shutdown of the facility.
In- -
clude in your report the results of all attempts to
" operate the two-stage S/R valve (s)."
Respon'se: Vermont Yankee has not installed, and has no plans to in-
. stall in the near future, Target Rock two-stage S/R valves with the Target Rock two-stage solenoid actuator. We pres-,
ently have four Target Rock three-stage S/R valves with ASCO~ solenoid operators. This item, therefore, does not apply to Vermont Yankee.
8104080 W 9
VERMONT YANKEE NUCLEAR POWER CORPORATION United States Nuclear Regulatory Commission March 19, 1981 Page 2 Item 2 "In the event that a S/R valve, regardless of make or model (e.g., both two or three stage), fails to function as designed, excepting for pressure setpoint requirements, and the cause of the malfunction is not clearly deter-mined, understood, and therefore corrected, standard oper-ating procedures shall require that the entire valve be removed from service, disassembled, inspected, adjusted, and pressure setpoint tested with steam for proper opera-tion prior to returning the valve to service.
These over-haul requirements shall be at least equivalent to those applicable to periodic surveillance rehabilitation re-quirements. Appropriate revisions to your operating pro-cedures shall be made to include these requirements."
Response: The actions required describe Vermont Yankee's standard operating practice.
There may be circumstances under which a modified approach may be appropriate and would be followed.
It would not be appropriate to include these requirements in our operating procedures.
Item 3 "A review of your S/R valve pneumatic supply systems shall be performed to determine the potential for and magnitude of an overpressure condition. The determined overpressure potential of the pneumatic supply shall be compared with the maximum operating pressure capabilities of the sole-noid actuator valves serving the S/R valves, so as to de-termine whether supply pressure could result in valve mal-function. Protective devices (such as relief valves) shall be installed in the proximity of.the S/R valves and set to protect against supply pressure in excess of the operating pressure capabilities of the solenoid actuator device.- In addition, consideration shon1d be given to modification or replacement to reduce the-sensitivity of the solenoid actu-ator to pneumatic supply overpressure. Further, the failure, either high or low, of the pneumatic supply system shall be annunciated to the Control Room operator. The annunciated supply pressure should be measured at a loca-tion as close as practical to the S/R valves and downstream of any check valve' connecting two or more pneumatic sources.
Appropriate. operating procedures ^shall be provided to guide operator response to such an occurrence of high or low supply pressure."
Response:.The instrument air system operates between 95 and 110 psi
.and is regulated by pressure switch activated compressor
. unloaders. The system is further protected by a series of s'
\\p
s
~.
VERMONT YANKEE NUCLEAR POWER CORPORATION United States Nuclear Regulatory Commission March 19, 1981 Page 3 pressure relief valves set at 150 psi. Tests conducted by our Instrument and Control Department demonstrate that rhe ASCO solenoids function properly at pressures in excess of 150 psi. We conclude that the air supply system to the solenoids is adequately protected against over pressuriza-tion.
Although we currently have low air supply pressure alarms in the Control Room, we will modify our annunciator system to indicate both high and low pressure in the instrument air system. Vermont Yankee expects to have this modification completed, and the appropriate oper-ating pro,cedure revised, by the end of the 1981 refueling outage.
We.will report the completion of this modification, in a supple-ment to this response at that time.
The following information is submitted in response to your re-quest for estimates of manpower expended in the research and subse-quent performance of actions associated with this bulletin.
Manpower Requirements Man-Hours Bulletin Response 45 Corrective Actions 0
We trust that the'above supplied information and our commitment to modify the annunciator system during the 1981 refueling outage is satisfactory; however, should you desire additional information, please contact us.
Very truly yours, VERMONT YANKEE NUCLEAR POWER CORPORATION William F. Con ay Vice President and Manager of Operations STATE OF VERMONT
.)
) ss WINDHAM COUNTY
)
Then personally appeared before me, William F. Conway, who, being duly sworn, did-state that he is a Vice President of. Vermont Yankee
. Nuclear Power Corporation, that he is duly authorized to' execute and file the' foregoing request in the name and on the behalf of Vermont Yankee Nuclear Power Corporation, and that the statements therein are true to the best of-his knowledge and belief.
Ubl A$
MI.
Judi
'A. Harris Notary Public My Co ission Expires February 14, 1983
.