IR 05000271/1993013
| ML20058M451 | |
| Person / Time | |
|---|---|
| Site: | Vermont Yankee File:NorthStar Vermont Yankee icon.png |
| Issue date: | 12/08/1993 |
| From: | Linville J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | Reid D VERMONT YANKEE NUCLEAR POWER CORP. |
| References | |
| NUDOCS 9312200333 | |
| Download: ML20058M451 (3) | |
Text
{{#Wiki_filter:_.
_.
- . -_ _.
_ _ _ __- _ .,
- ..
. .! y Q, ~ _ .
r l . DEC 8 1993 i
I ! Docket No. 50-271-l
.. i Mr. Donald Reid ! Vice President, _ Operations '] Vermont Yankee Nuclear Power Corporation , RD 5, Box 169 > t Ferry Road 13rattleboro, Vermont 05301
!
Dear Mr. Reid:
l i t SUBJECT: INSPECTION 50-271/93-13
a This letter refers to your August 19, 1993 correspondence, in response to our July 22, 1993 l letter regarding a violation for the improper calibration of core spray sparger differential- { pressure instruments.
The effectiveness of your corrective and preventive actions will be examined during future ! inspections of.your licensed program.
~ Your cooperation with us is appreciated.
'! i
Sincerely,
! Original fi6aed 4 i Jernes 4 Lifwille' 'i ! James C. Linville, Chief - a Reactor Projects Branch 3 j Division of Reactor Projects ' , cc: R. Wanczyk, Plant Manager J. Thayer, Vice President, Yankee Atomic Electric Company .. i
- ll 140086
[ 9312200333 931208 II OFFICIAL RECORD COPY / \\( I PDR ADOCK 05000271 N l Q PDR ti. - - - .. .. - -. -
m L-J r.
_ .* p- ,
s p'. I . ! + - phm.,s - , , -, .,. k i, i t i ', I +
1 ?
. e , " f !
> t i s k ' t ! ,
's I Mg kh f - f $ ' ,
f L f i f f I ! i
J '! t I ! ! t
} ! ,+ - p ,, 3,4 '. J 4_ i '. " t J i l V 6[( O f(M4 )[[.dN LI A IIII'Udk k . t - - '
i
..
r , i - DEC 8 1993 , , Mr. Donald Reid
l cc w/cy of Licensee's Response Letter: L. Tremblay, Senior Licensing Engineer, Yankee Atomic Electric Company J. Gilroy, Director, Vermont Public Interest Research Group, Inc.
i D. Tefft, Administrator, Bureau of Radiological Health, State of New Hampshire . Chief, Safety Unit, Office of the Attorney General, Commonwealth of Massachusetts R. Gad, Esquire ! G. Bisbee, Esquire j R. Sedano, Vermont Department of Public Service ! T. Rapone, Massachusetts Executive Office of Public Safety Public Document Room (PDR) - Local Public Document Room (LPDR) Nuclear Safety Information Center (NSIC)
) K. Abraham, PAO (2 copies) NRC Resident inspector State of New Hampshire, SLO Designee < State of Vermont, SLO Designee Commonwealth of Massachusetts, SLO Designec ! ! . t e i I ' i
1 l .
OFFICIAL RECORD COPY , -- .
. _. ._ . . .. _. - .. ' > .,. _ - . ! Mr. Donald Reid '
DEC 8 1993 i '
bec w/cy of Licensee's Response Letter: , Region I Docket Room (with concurrences) ^ E. Kelly, DRP J. Shedlosky, DRP ! B. Whitacre, DRP W. Dean, OEDO '! D. Dorman, NRR W. Butler, NRR , t , l '
, . ? I ! ! ! .
, P P i
i i
Rl;DRP RI:I RP p,' yelly mv e tr ' 12/8/93 /*8 & / OFFICIAL RECORD COPY A: REP 9313.MEO
...
.* ] , . VEstMON' YANKEE N' C, LEAR POWER CORPORATION U . Ferry Road. Brattleboro. VT 05301-7002 ,* 8tEPLY TO y ENGINEERING OFFICE
580 MAIN STREET , , BOLToN. MA 01740 , * * '" August 19, 1993 BVY 93-86
United States Nuclear Regulatory Commission ATTN: Document Control Desk . , Washington, DC 20555 . $ License No. DPR 28 (Docket No. 50-271) References: a) , b) Letter, USNRC to VYNPC, Inspection Report 93-13, dated 07/22/93 .
Dear Sir:
~
t Subject: Reply to Notice of Violation - Inspection Report 93-13
This letter is written in response to Reference b), which documented that one of our activities was not conducted in full compliance with NRC requirements. The Violation was identified and reported by "_.
station personnel in Licensee Event Reports 93-006 and 93-009 and in NRC Inspection Report 93-13. ' Our response to the Notice of Violation is provided below.
VIOLATION: - " Technical Specification 3/4.2.A., Table 3.2.1 requires, in part, that the core spray high sparger pressure instruments be calibrated to a setpoint of less than or equal to S pounds per square inch differential pressure (psid).
Contrary to the above, on May 27,1993, Vermont Yankee determined that due to improper - calibration of the core spray high sparger pressure instruments, both the "A" and "B" ' .
instrument setpoints exceeded the Technical Specification limit. This condition existed since November 1979.
- Ihis is a Severity Level IV Violation (Supplement I)."
RESPONSE: Based on our root cause analysis, this event occurred as a result of personnel error in applying the required head correction to the differential pressure indicator, but not the alarm point. Since there - is no direct correlation between the alarm setpoint and the indication, the head correction did not affect the alarm setpoint which remained non-conservative. Failure to apply the head correction to the alarm setpoint resulted in an actual alarm setpoint greater than the Technical Specification limit. The differential pressure indicator correction was first applied in 1979 in response to General Electric SIL.
300.
z f.
, . ..
_ -_ ' . . ,
U.S. Nuclear Regulatory Commission VERMONT YANKEE NUCLEAR POWER CORPORATION' August 19, 1993 ! Page 2 Our root cause analysis also revealed that the Vermont Yank.ee Technical Specification may be non-conservative. SIL 300, states that the maximum expected differential pressure across the reactor vessel shroud during a core spray sparger break is expected to be 4 psid. He Vermont Yankee Technical Specifications state that the differential pressure setpoint should be 15 psid.
_ CORRECTIVE ACTIONS: e Immediate: On May 28,1993, an interim administrative setpoint of14 psid for the Sparger Break Detection sensors was imposed by Vermont Yankee management. In addition, the I&C staff prepared a minor change to the applicable procedure which instructed the I&C Specialist to read the trip point on the Barton differential pressure instrument, thus ensuring that the actual trip point was set at the adthinistrative limit i of 4 +/.3 psid. He I&C Specialists performing the work were verbally instructed to adjust the switches to the lower end of the limit, or 3.7 psid. His adjustment resulted in the switches being set such that they would trip prior to the expected maximum dp of 4.0 psid. After a review of the field ' calibration data, the core spray system was declared operable on May 28,1993.
He verbal communication to set the switches to the lower end of the limit or 3.7 psid was not incorpaated into the monthly calibration procedure, OP 4347, in a timely manner. Subsequently, during the June and ' July surveillance tests, one of the switches was found to have drifted above the i adtuinistrative limit of 4.0 psid without the core spray system being declared inoperative. Concurrent , with the July performance of the surveillance procedure, a review conducted by the Resident NRC - Inspector and a corporate review of LER 93-06 prompted l&C management to more closely examine the surveillance test data. On July 16,1993, the "B" Core Spray System was declared inoperative due to , an "as-found" d/p of greater than 4.0 psid. He differential pressure switch was reset to 3.7 psid and the ' system was returned to service. The calibration procedure was formally changed at that time to require these switches to be set to 4 +0/.3 psid.
. . 12mg Term: = The I&C Procedure Writer's Guide, AP 0310, will be revised to instruct procedure writers and 1.
reviewers to include a sec6on that details the setpoint determination and includes any offsetting or head corrections as a sparate section. This will be completed by September 1993.
2.
Procurement requests have been submitted to purchase two new Barton Differential Pressure Indicating Switches, with an indicating range of -5 to +5 psid to better suit the application.
Reviews that Other I&C calibration procedures will be reviewed for similar discrepancies.
3.
address other Barton instruments have been completed and the. remainder of the procedure
reviews will be completed by October 1993.
l i De Core Spray Sparger Break Detection System design basis and licensing review of the 5 psid 4.
If this review Technical Specification setroint value will be completed by September 1993.
indicates that an amendment to the Technical Specifications is necessary, a proposed change will , be submitted.
, . . .
. , _ - .. _ _ . __ _ .. .7-e . . ' ' h.S Nucleart'egulatory Commission - VERMONT YANKEE NUCLEAR POWER CORPORATION ' August 19,1993 , Page 3 ' ,
5.
Each Vermont Yankee depanment has been instructed to develop a department specific, self-assessment program to ensure there are mechanisms in place to maintain ongoing cognizance of i industry experience developments, i We trust the information provided is adequate; however, should you have any questions or require ' I additional information, please do not hesitate to contact us.,
Sincerely,
) Vermont Yankee Nuclear Power Corporation Paal , - . - , James P. Pellaier Vice President, Engineering l /dm ~ i i cc: USNRC Region I Administrator
USNRC Resident inspector - VYNPS USNRC Project Manager - VYNPS j , i ,
! ! E %
- i l
j !
e
s ; I t ! I s i !
I .
-.- . - -. . }}