IR 05000267/1988012
| ML20154L863 | |
| Person / Time | |
|---|---|
| Site: | Fort Saint Vrain  |
| Issue date: | 09/14/1988 |
| From: | Callan L NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | Robert Williams PUBLIC SERVICE CO. OF COLORADO |
| References | |
| NUDOCS 8809260323 | |
| Download: ML20154L863 (2) | |
Text
,,,.
.
.
- _.
..
. _.
.
'
@ l4 g
..
In Reply Refer To:
Docket:
50-267/88-12
.
Public Service Company of Colorado ATTN: Robert O. Williams, Jr.
Vice President, Nuclear Operations
2420 W. 26th Avenue, Suite 15c
.
Denver, Colorado 80211 l
Gentlemen:
Thank you for your letter of August 11, 1988, in response to our letter and Notice of Deviation dated July 6, 1988. We have reviewed your reply and find it responsive to the concerns raised in our Notice of Deviation. We will review i
I the implementation of your corrective actions during a future inspection to
determine that full compliance har, been achieved and will be maintained.
l
Sincerely,
!
OQinal kned By:
j L J. CALLAN
)
L. J. Callan, Director l
Division of Reactor Projects
,
i cc:
[
I Fort St. Vrain Nuclear Station
!
t Manager, Nuclear Production Division
16805 WCR 191
,
'
Platteville, Colorado 80651 l
Fort St. Vrain Nuclear Station
!
P. Tomlinson, Manager Quality
'
'
l Assurance Division (sameaddress)
Coli o Radiation Control Program Director
,
i Colorado Public Utilities Comission l
bec to DMB (IE01)
)
RIV:PSB C:PSB D:
f TFWestertnanLJCallan j
RPMullikinpif j
9/19/88
/
9//y/88 9/g/88 g82'"$8858"d'a7 j
.
.
.
,
.
Public Service Cornpany of Colorado-2-bec distrib by RIV:
RRI R. D. Martin, RA SectionChief(DRP/B)
Project Engineer, DRP/B RPB-DRSS Lisa Shea, RM/ALF MIS System RSTS Operator
,
!
K. Heitner NRR Project Manager RIV File DRS DRP
,
I
-
.
-
-
-
-
-
-
l j@[I! fl.k../.65 3 i
-
,e
-
.
L{u
. ~ h.
ALE 2 31988
_ L+ ::=y,',n,.
Public Service-16805 WCR 19 1/2, Platteville, Colorado 80651 August 11, 1988 Fort St. Vrain Unit No. 1 P-88292 U. S. Nuclear Regulatory Commission ATTN:
Document Control Desk Washington, C.C.
20555 Docket No. 50-267 SUBJECT:
NRC Inspection Report 88-12 REFERENCE: 1) NRC Letter, Callan to Williams, dated July 6, 1988 (G-88265)
Gentlemen:
This letter is in response to the Notice of Deviation received as a result of the inspection conducted by Messrs. R. E. Farrell, P. W. Michaud and K. L. Heitner during the period Ma; 1-31, 1988 ( Re f. 1).
The following responses to the items contained in the Notice of Deviation are hereby submitted.
The licensee, by letter to the NRC Region IV dated July 10, 1985, committed to compliance with the interim Technical Specification,
' 4 ting Condition for Operations (LCO)
3.1.1.C.
and to
,
surveillance requirement (SR) 4.1.1.A.2 which require the following:
Maintain a helium purge flow to each control rod drive
-
penetration when reactor pressure is above 100 psie.
?g
,,
,,.,o~?
?
--
L v (.4 l (f
"*
Ic - M vg
fi P-88292-2-August 11, 1988
,
l e
Verify at least once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> that the purge flow is
-
'
-
.
maintained to each control rod drive mechanism when reactor
-
pressure is above 100 psia.
In deviation from the above commitment:
The NRC inspector observed on May 18 and 19, 1988, with
-
reactor pressure greeter than 100 psig, that the helium purge flow indicated to the subheaders on flow instruments FI-11268-3, -4, and -7 was reading zero or below. Also, the flow to individual control rod drive penetrations indicated zero or below zero.
The reactor building equipment operator's log sheet only
-
required that subheader flow be greater than zero which does not account for inttrument error or assure that a helium purge design flow at full density helium of 5.5 lbs/hr per penetration will be maintained.
(1) The Reason For The Deviation If Admitted:
The deviation is admitted.
On May 19, 1988, with reactor pressure at 171 psig FI-11268-3 and-7 were observed by the licensee to be zero, and FI-11268-4 was observed to be less than zero. Also, individual flow instruments, FIT-1127-5,
-8,
-13-27 and -32 were less than zero, and FIT-1127-16 was reaoing zero (See Attachment 1 for reference drawing).
The deviation was caused by a defective flow element, FE-11265, which controls FIC-11265 that sends a signal to flow valve FV-11265, which controls helium flow to the control rod drive (CRD) purge flos header.
FIC-11265 is set at 7.4 ACFM to mair.' in about 5 lbs/hr
,
f (FSAR 3.8.1.1.1)
at 700 psia to the CRD penetrations (See Attachment 2). When the eight (8)
subheader flow indications were added together, the total flow was found to be 2.87 ACFM (indicated). When the individual flow elements (FIT-1127-1,
>
-2,
. -37) were added together, the total flow was 2.43 ACFM (indicated) or about 0.3 ACFM per subhearier flow instrument.
From this, PSC concludes that the he;1um flow entering the penetrations was considerably less than 7.4 ACFM, as indicated on FIC-11265.
The flow element was giving a higher than actual differential pressure signal to the flow indicator / controller.
This is believed to be caused by a defective (partially blocked or damaged) flow element.
In addition, FI-11268-4 and -7 were found to have drifted out of calibration, and the individual flow elements were found to require ralibration and zero adjustment.
The combination of low penetration flow and calibration drift resulted in the low flow indications that were observed on the flow indicators.
_ _ _ - _ _ _
- - _
- -.
.-.
___ - _ - - - -.. - -_. - - - - - -. -
.
.
- _
_ _
-
P-88292-3-August 11, 1988
,
l
-
'
!
In the second instance of the deviation, interim Technical
'
Specific & tion, Limiting Conditions for Operations (LCO)
3.1.1.C only requires that purge flow be maintained to each control rod
.
drive assembly by verifying purge flow in each subheader.
As long as there was positive indication on the subheader flow
iridicators (FI-11268-1,.. -8), LCO 3.1.1.C was presumed to have
.
been met.
j
<
Also, a review of the System Operating Procedure (SOP) 12-06 has
revealed a discrepancy.
The original SOP 12-05, which contained
j the operating procedures for both CRD purge flow and reserve shutdown system purge flow, had a graph which identified the
'
,
minimum design purge flow at any given reactor pressure.
When
,
the CRD purge flow procedure was removed from S0P 12-05 and
>
rewritten as 50P 12-06, the graph was inadvertently deleted from
!
j the procedure.
This removed any reference of design purge flow t
as an operator aid.
(2) The Corrective Steps Which Have Been Taken And The Results Acnieved:
q
.
The immediate response was to increase the helium flow to the I
penetrations by increasir9 the setting on FIC-11265 until
'
sufficient flow was establiRed. An indicated setting of 17 ACFM
'
was needed to bring the total control rod drive penetration flow
back to within the design specification of 7.4 ACFM.
The piping i
i between the flow control valve (FY-11.265) and the subheader flow
i transmitters was checked for leaks to ensure there was not a loss
!
l of helium flow between those two points.
The increased flow
!
produced positive readings on all eight (8)
subheader flow
[
i indicators, and positive readings on all but 1 of the 37 i
j individual flow indicators.
FIT-1127-27 still had an indication of le:s than zeru.
The flow indicator / transmitter was I'
electrically zero'd per manufacturer's procedure.
The flow
)
indicator / transmitter was found to be out of tolerance by over 2.0 SCFM which accounted for the negative reading.
'
During the current circulator outage, the eight (8) subheeder l
flow instruments were calibrated using SR 4.1.1.f.la-R.
Flow I
transmitters FT-11268-1,
-2,
-4,
-5,
-7 and-8 required adjustment.
Flow indicators FI-11268-1, -4 and -8 also required j
djustment.
The surveillance also called fo~ the calibration of i
/TC/FY-11265.
The indicator / controller was found to be within
!
the acceptance criteria but the flow element itself could riot be 1-checked in place.
i i
No similar incidents have occurred since the corrective steps j
described above were taken, a
r
j
!
i
..
_ _
_,._
_ _ _ _ _.. _ _ - _.. _, _.. _ _ _ _.. _ _ _ _ _., _ _ _
_ _ _.
_ _ _ _ _ _..
-.
_ -.
--
- _ _ _ = _ - _
-
-.
--
-
--
_--
_-
P-88292-4 Augu.-
11, 1988
,
,
'
<o
,
I (,1) The Corrective Steps Which Will Be Taken To Avoid Furthc,r
'
t violations:
-
j CRD helium purge flow will be verified to both the CRD purge flow
,
subheaders and to the 37 individual CRD penetrations on a daily r
basis to ensure that balanced flow is present to the CRD
,
i penetrations.
These checks, as well as absolute minimum design
j flow requirements, will be added to the operator's daily logs to
!
accomplish this verification.
If the equipment operator l
i discovers a
single penetration with imbalanced flow, an f
d adjustment will be made using the manual flow control needle
]
valve to obtain balanced flow consistent with the remaining flow i
!
to the other individual penetrations.
The adjustment of these i
valves is addressed in 50P 12-06.
i A new quarterly preventive maintenance item will be created to i
periodically monitor and correlate the flow readings of l
,
)
FIC-11265, the eight subheader flow indications and the 37
individual penetration flow indications with PCRV pressure.
This
!
correlation will provide periodic reviews to ensure that the t
,
i three redundant flow indications are in agreement and identify l
any potential out-of-calibration instruments or flow element
'
j problems.
,
i l
Defective flow element FE-11265 is scheduled to be replaced by a
'
calibrated flow element during the current circulator outage.
A
!
j new procedure (RP-RE-17?-R) will be used to calibrate the (
individual flow elements (FE/FIC 1127-1 through -37) durino the
,
circulator outage.
l
,
I Procedure 12-06 will be revised to incorporate the PCRV pressure j
/CR0 purge flow correlation graph previously deleted from
!
j Procedure 12-05,
-
j t
i Improvement of the operator's daily checks, replacement of the
!
j defective ficw element, and establishment of the new maintenance i
action to monitor and correlate redundant flow indicators is l
{
considered to be sufficient to prevent recurrence of this j
incident.
!
!
No additional corrective action is necessary for the control rod l
drive purge flow problem.
t
)
(4) The Dg e When Full Compliance Will Be Achieved:
a l
All repairs and technical changes to the 50P and Equipment l
i Operator's logs will be completed by the end of the circulator
!
outage presently scheduled for the end of September,1988, i
)
!
I l
l
!
'
l
'
.
I
.-
-
-
-
.
-
-
-
-
-
_ - _ _ _ _ _ _ _ _ _
P-88292-5-August 11, 1988
,
b Siiould -
you have an further questions, please contact
'
Mr. M. H. Holmes at (303) y480-6960.
Sincerely, A 0 lfLkl R. O. Williams, Q
Vice President, Nuclear Operations R0W:BCL/skd Attachments cc:
Regional Administrator, Region IV ATTN: Mr. T. F. Westerman, Chief Projects Section B Mr. Robert Farrell Senior Resident Inspector Fort St. Vrain i
i
l l
l
!
_ _ - _ - _ _ _ - _
_ - - - - -
-
.
.
.,
-
e HTTRCi!NENT I TO P-00292 A
r
?>
FIC 112G5
'
J
>
2G5 harafled
\\
/
erbte i Heleum )
FT To Individual (Typical)
Flow Control N
11268 CRD tJeedle Valve
Header pg g
o (Typical
>
Penetrations i1205 SA>he ade r )
,
p b
G
-
oe E
-
J V
tbte I:
SAhe ade r s FI-i l 200 -1,-2. -5,
-6, and-7, provede flow to 5 indevedual CRD penetrattons e ac.h.
SAhe ade r s F I-i l 2G8-3. -4-0, prov e de flow to 4 endovedual (
CRD penetratsons each.
- -
- _ _ _ _ _ _ _ _ _ _ _ _ _ _
_
'
o.
. ' '..
- *
,
ATTACHMENT 2 Calculation of the minimum flow requirement.
Density of helium (D) = Pressure (P)/(Temp (T) X Gas Constant (G))
G = 366.2 FT-LBf/LBm-R P = 700 psia T = 105 + 460 = 565 R D = 700X144( conversion sq in to sq ft)/(565X386.2) =.462 lb/cuft Total flow in LB/HR = 7.4 ACFM X.462 lb/cu ft X 60 min /hr
= 205.1 lb/hr Flow per drive unit = 205.1 lb/hr / 37 penetrations
= 5.54 lb/hr per drive unit.
Note:
FI-11268-1,
-2,
-5,
-6 an'* -7 provide flow indication for those helium purge subheadt's which supply five CRD penetration; each.
FI-11268-3,
-4 and-8 provide flow indication for those helium purge subheaders which supply four CRD penetrations each.
Each CRD penetra tion is supplied a helium purgt flow of 0.2 ACFM.
There fore,
!
FI-11268-1,
-2, -5, -6 and -7 should each indicate a helium purge subheader flow of 1.0 ACFM, and FI-11268-3, A and-8 l
should each indicate a helium purge subheader flow of 0.8 ACFM.
'
-