ML20050A929

LER 82-007/01T-0:on 820309,calculations of Standby Liquid Control Storage Tank Concentration Versus Tank Level Correlation Did Not Account for Specific Gravity of Sodium Penaborate.Procedures Corrected

ML20050A929
Person / Time
Site:	Vermont Yankee
Issue date:	03/23/1982
From:	Murphy W VERMONT YANKEE NUCLEAR POWER CORP.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20050A928	List: ML20050A927 ML20050A929
References
LER-82-007-01T, LER-82-7-1T, NUDOCS 8204020409
Download: ML20050A929 (2)

Text

-

(7 T/l LICENSEE EVENT REPORT LER 82-7/lT CONTnOtetOCoI l l l l l l@ (PLEASE PRINT OR TYPE ALL REQUIREO INFORMATION) lOIiI lv ITLICEMEE lv lY IS l1 l@l010l-l0l0l01010l-l010 l@l4l111l1l1l@l 25 26 LICENSE TY PE JD l

Si CAT de Ig I

d 9 LOCE 14 1$ LICENSE NLYSER CON' T loli]

1. 4

(('] l L&J@l 0l 5 l 0 lDOCKET 61 0 l 0NUVSEi4 l 2 l 7 l 168@l690 l3EVENT l0 l9 l8 l2 @l 0 l 3 lREPORT DATE 74 75 2 l 3DATE l 8 l 280l@

EVENT DESCRIPTION AND PROBABLE CONSEQUENCES h 10 121 I l See Attached, j

[o ;3 ; L l

1 o 141 I 10151 1 I 10161I I .

I l

lo 17 I I _

l 10181 1 80 1 8 9 STSTE\1 CAUSE CAUSE COMP. VALVE CODE CODE SUSCODE COMPONENT CODE SU8 CODE SU8 CODE lol9l l P l C lh l D lh l Zlh l Z l Z l 7, l Z l 7, l Z lh l Z lh W h 18 19 20 i 8 9 10 11 12 13 SEQUENTI AL OCCURRENCE REPORT REV;SION

_ EVENT YEAR REPORT NO. CODE TYPE NO.

h l"g 'l49; a og l 8l 2] l-l l 0l 0l 7l l/l l0 l1 l lTl l-l l0l 21 22 2J 24 26 27 28 23 30 31 32 T A T

• ON PL T kTH HOURS SB IT D FOR1 B. SUPPLIE MANU AC URER lGl@lZl@

31 J4 lJoZ l@ lZl@

J6 l0l0l0l0l 34 40 lYl@

41 1]@

42 lZ 43 l@ lZ 44 l9 l9 l9 47l@ l CAUSE DESCRIPTION AND CORRECTIVE ACTIONS l

11 101 l lilij l See Attached. j i1Iil I lilli l d i

I I1 141 l 7 8 -)

80 ST S . POWER OTHER STATUS ISCO RY DISCOVERY DESCRIPTION I1 15 l l El@ ll l0 l0 lhl NA l lBlhl Procedtiral Review l A TlVITY CO TENT nELE ASEo Os nELE ASE AYOUNT OF ACTIVITY LOCATION OF RELE ASE NA l l1 l63 3] W @ d@l 7 10 11 NA 44 l l 45 80 PERSONNEL EXPOSURES NUY9 E R DESCRIPTION l t ] 7 ] l 0 l 0 l ' 0 lhlTYPEZlhl '

NA

' " ' 2

, PE RsONNe'L INJu' RIES i No.mER.

oESCRiPTiON@

ji l-ll0l0l0!hl NA l i 8 9 11 12 80 j

i LOSS OF OR DAVAGE TO FACILITY TYPE DESCRIPTION l Q lZl@l 7 8 '3 10 NA 80 l

"' * ' M T V Q NRC USE ONLY 2 o a

K Ohh NA l llllllllll lllf

• 3 i .

PDR NAME OF PREPARER

" " ~ *

• PHONE: (802) 257-7711 {

{_

e -

VTVYS1 05000271 LER 82-7/lT Event Description and Probable Consequences A review of the SLC System procedures for controlling sodium pentaborate concentration in the SLC storage tank revealed the following deficiencies:

1. The SLC storage tank concentration vs. tank level correlation  ;

did not account for the specific gravity of sodium pentaborate. This resulted in a nonconservative error of approximately 5% when determining sodium pentaborate solution volumes.

2. The specific gravity of the SLC solution was not previously considered in the SLC concentration calculation. This resulted in an additional nonconservative error of approximately 5%.

Due to these 2 calculation errors, VY may have been unknowingly below the T. S. 3.4 limit end, therefore, is reporting this event in accordance with T. S. , Sec tion 6. 7.B. l. i.

There were no consequences of this event. At all times, the SLC System had sufficient concentration to 390 vide its intended shutdown function. However, it does constitute a situation in which a system required corrective action to prevent operation in a manner less con-servative than assumed in the accident analysis.

Cause Description and Corrective Action Plant management took the following corrective action:

1 The affected procedures were immediately corrected.

2. The sodium pentaborate concentration in the SLC tank was increased to well above the Tech. Spec. Limits (as a result of LER 82-3).

3. A task force was established to investigate and resolve the following:

a. Boron concentration history,

b. Procedural review of SLC System procedures,

c. Level instrumentation calibration,

d. Design basis for'SLC concentration / volume.

NOTE: Corrective actions taken (as a result of the task force report) will be documented in a followup report.

i . .. . .

.