IR 05000373/1990013
| ML20055D976 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 06/27/1990 |
| From: | Greger L NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML20055D973 | List: |
| References | |
| 50-373-90-13-MM, 50-374-90-14, NUDOCS 9007100217 | |
| Download: ML20055D976 (6) | |
Text
7 e
"
..
,
.
, q
.
j
.
,
~,
h U.S. NUCLEAR. REGULATORY COMMISSION p.
i.
REGION III
L
'
- Reports No. 50-373/90013(DRSS);50-374/90014(DRSS)
Docket Nos. 50-373; 50-374 Licenses No NPF-11; NPF-18 V
'C Licensee: Commonwealth Edison Co.
.
P.O. Box-767 a
Chicago, IL 60690-
'
Facility: LaSalle County Station Units 1 and 2
- Meeting At: _ Region III Office
.
~
Meeting Date: May 30, 1990
. Approved By: L
. Greger, Chief
'
q Reactor Programs Branch e
i Meeting Summary:
Meeting on May 30', 1990'(Reports No. 50-373/90013(DRSS);-50-374/90014(DRSS)
i f,
Areas Discussed: A special management meeting was conducted.to discuss-the
radiological status of LaSalle-radwaste tank rooms _and licensee plans to clean--
up floor contamination-and to avoid future significant floor contamination
~
in the-rooms.
In addition, the licensee's health physics evaluations in support
~of. work-performed.in'these rooms were discussed,
,
n
_Resul ts :
Significant quantities of radioactive sludge and resins exist on-the floors'of six.radwaste tank rooms. These conditions have been long -
. standing and resulted from tank ovet flows in the past when liquid input.to radwaste. exceeded-processing capacicy or when equipment' failed..The.last such overflow was in 1988.
Cleanup of the rooms was not performed due to infrequent room entry.- The licensee will now proceed with the cleanup and will provide a
-
schedule for completion. One violation was identified for inadequate-
'o evaluation of potential extremity dose. (Section 3)
e C
'9007100217 900628 r
.
{
tn
,
+
>
.;
,
,
,
,
,
..'
'
y
,
,
.*
!
c
.,
,
,
'
.c r
DETAILS y
!
,
1.
Meeting Attendees
~
!
'
Commonwealth Edison Company K. Francis, Radwaste Coordinator, LaSalle T. Hammerich, Regulatory Assurance Supervisor, LaSalle D. Hieggelte. Health Physics Supervisor, LaSal'le X..
W. Huntington, Technical Superintendent, LaSalle
.
T. J. Kovach, Nuclear Licensing Manager,-CECO
?
W.LMorgan, Nuclear Licensing LaSalle
.
F.-Rescek, Radiation Protection Director, CECO
't
- J. Schrage, Health Physics Supervisor, NSRP, Ceco i
,
"
Nuclear Regulatory Commission
.
R.'Greger, Chief, Reactor Programs Branch, Region III l
J.-_ House, Radiation Specialist, Region III
,
A. Januska, Senior Radiation Specialist, Region III C. Norelius Director Division of Radiation Safety and Safeguards,
,
Region III-
-
R. Pulsifer, Project Manager, NRR
.M. Schumacher, Chief, Radiological Controls and Chemistry Section, i
Region 111
'
T. Tongue Senior Resident Inspector, Region !!!
2.
Introduction l
During a recent ALARA team inspection at LaSa11e, NRC inspectors noted
,
significant quantities of contaminated sludge;and resin on the floor of
the room housing and the Waste Sludge (WS) and Ultrasonic Resin Cleaner
(URC)S These conditions were similar to those identified at
- Dresden}udgetanks.
.
in that the conditions were long-standing and had resulted from
'
tank overflows and other radwaste system operating difficulties over a
,
number of years. The licensee was requested to meet with NRC
representatives in Region III to discuss the radiological status of the radwaate rooms generally. the licensee's plans for decontamination and L
avoidance of future overflows, and the licensee's health physics-L evaluations in support of work in these rooms.
3.
Meeting Details I
h Licensee representatives identified six radwaste tank rooms having floors
.
that are contaminated with significant quantities of sludge and/or resins.- Average depths ranged from one-half inch in the Radwaste Discharge Tank room to an estimated two inches in the Chemical Waste Tank
.
(CWT) and Waste /URC Sludge Tank rooms.
The contaminated materials were-
>
'1
.
Inspection Reports No. 50-373/90008 DRSS ; 50-374/90009 DRSS
Inspection Reports No. 50-237/89020 DRSS ; 50-249/89019 DRSS
I I
I
-.,..
-
.
.-
..
,
.
mainly the' result of tank overflow and sump backup into the tank rooms at
'
.
times when liquid input to radwaste, particularly from floor drains, exceeded processing capacity.
This condition was exacerbated by evaporator problems such as excessive solids input and valve failures, sludge processing difficulties, poor sump maintenance, and poor control of sludge and liquid levels in tanks and sumps. Licensee representatives acknowledged that tank overflows and resin backups into the radwaste tank rooms were knowingly allowed as an operational exigency during the conditions described above but stated that it was not a planned mode of operation. Recent licensee photographs of the tank rooms showed dried sludge and resins on the floors as described. They showed no apparent standing water but watemarks indicated possibly as much as a foot of water and/or sludge depth in the past.
Licensee _ representatives emphasized that significant radwaste system and-operating improvements have been made in the past few years and that the last such overflow event occurred in early 1988.
Evaporator performance has been upgraded significantly to near design capacity. This was achieved largely by discontinuing the regeneration of demineralizers, which resulted in improved water quality generally, reduced solids
'
carryover and by installation of acid resistant valves. More recently, floor drain inputs to liquid radwaste were reduced from 10 gpm to about 4 gpm, making normal system throughput well within the processing capacity of the evaporators. Other contributing improvements were the use of a vendor to help with sludge processing, better sump maintenance through better cleaning, better control of sludge and iiquid levels, installation of improved level indicators, improved training of radwaste and operations staff, and development of an in-plant chemical control procedure.
Licensee representatives dest.ribed the radiological status of the six radwaste rooms.
In general, room average dose rates ranged from about 70 mrem /hr in the Radwaste Discharge Tank rooms to about 3000 mrem /hr in the Unit 1 Chemical Waste Tank and the Waste /URC Sludge Tank rooms.
Entry to these rooms was said to be well controlled and generally made only in conjunction with maintenance or for visual inspections by operators and supporting radiation surveys which are normally done frcm tleentryway(.
The licensee presented collective dose and man-hour information. sunnarized in Table 1) based on RWP records that sNwed that four of the six rooms had recorded dose in only one of the year; from
,
.1985-1990. The most significant of these was 4.2 person-rem in:urred in the Unit 1 Floor Drain Tank room in 1988 while removing sludge buildup in tanks; the remainder had recorded doses of less than one persor-rem.
The other two rooms, the Unit 1 CWT and Waste /URC Sludge Tank rcoms, had recorded doses of 1.6 and 18 person-rr, respectively, acctmulated in four of the years from 1985-1990.
The latter dose resulted mainly from
' installation of new air spargers in 1987, installation of in-tank mixers in-1989, and inspection and maintenance related work in 1990. Although entries to the six rooms are relatively infrequent, the licensee intends to decontaminate them now that ligt.id radwaste processing appears to be under control.
'
L
.. _ _... _. _........
'-
- ..
<
.
In 1987, the licensee discovered that the supports for the Unit 1 Chemical Waste Collector and Process Tanks were leaning (off-plumb) about five degrees from the vertical owing, apparently, to the effects of past overflows of low pH water into the room and resultant deterioration of the tank supports. The tanks are not currently being used; they are on stand-by for emergency use only until the problem is corrected. The licensee plans to repair these tanks after decontaminating the room fluor and transferring the removed sludge to the Waste Sludge Tank.
In addition, the licensee plans to obtain two portable tanks to provide emergencyLsurge capacity * ile the chemical tanks are unavailable.
g Completion of the work in the Chemical Wasta Tank room is expected by the end of 1990. The licensee then plans to complete the work in the other radwaste tank rooms, including room decontamination and the installation of new level indicators, by the end of 1991.
,
The licensee estimated that the completion of the repair and cleanup pmgram for the Unit 1 Floor Drain Tank _and the WS/URC Sludge Tank rooms V il' require 10 to 15 person-rems. This estimate anticipates the use of n remotely controlled robot for removal of sludge and resin debris from the floor. One of the jobs reviewed during the recent ALARA inspection at LaSalle was work done in the Waste /URC Sludge Tank room in preparation for use of the robot. _As described to the inspectors, it involved combing through the sludge / resin at depths up to perhaps as much as six inches to remove obstacles that could impede use of the robot.
The inspectors noted that the licensee's survey records for this work, which took place during the week of April 23, 1990, did not include measurements at floor level and that the workers were not provided with dosimetry for measuring dose to the lower extremities. Because the material on the floor may have included control rod drive (CRD) cleanup resins possibly_containing hot particles, this appears to have been an inadequate evaluation and contrary to the requirements of 10 CFR 20.201(b).
(Violation 50-373/90013-01; 50-374/90014-01)
The NRC inspectors also expressed concern during the ALARA appraisal that this work, done in the Waste /URC Sludge Tank room in preparation for use of the robot, for which a collective dose of approximately six person-rems had been approved, had gone forward without approval or consultation with-the corporate health physics group. During the current meeting, licensee representatives stated that the overall cleanup project would be well coordinated with the corporate group and that lessons learned from_a similar project in progress at Dresden would be incorporated. During the June 18, 1990, telephone call, licensee representatives agreed to provide the region with a copy of the completed ALARA reviews for this project including an" special radiation protection or ALARA procedures developed for it and a completion schedule. This matter will be followed in subsequent inspections.
(0 pen item No. 50-373/90013-02; 50-374/90014-02)
4.
Summary As a result of this management meeting, the licensee agreed to provide a copy of the completed ALARA review for the radwaste repair and cleanup program, including any required special procedures, and a completion schedule.
k
... _. _ _ _
_ _...
.3
.
.l*i r
.
Thelicenseewasinformedbytelephoneon' June 18, 1990, that a violation 7,.'
would be assessed for inadequate surveys (evaluations) ta, aetw.?ne extremity doses to workers in the Waste /URC Sludge Tank rc.-< cs:ci!q tra I
week of April 23, 1990.
Attachment: Table 1
'
i
_ _ _ _ _ - _ _ _ - _ _ _ _ _ - _ - _ -
_ _.. - -....
.
's.e
- *
.
...
..
TABLE 1 COLLECTIVE DOSE AND WORKING HOURS FOR RADWASTE TANK ROOMS
- '
ROOM
1985
1986 :
1987
1988 :
1989
1990 : TOTALS:
- U1 FD Tanks
- Person-Rem
0-
- 4.167
- 4.167 :
Person-Hours
132
132 :
- U2 FD Tanks
Person-Rem
- 0.072 :-
- 0.072 :
- -Person-Hours
3:
- U1/U2 Dish Tks :
- Person-Rem
- 0.122. :
- 0.122 :
Person-Hours
2:
- -
.:
- 01/U2 Coll Tks :
Person-Rem
- 0.051
- 0.051 :
Person-Hours :
4:
- U1 CWT Room
Person-Rem
- 0.095
- 0.144 : 0.838 :
- 0.478 :
- 1.555 :
Person-Hours :
- 1.4
7 -:
- 22.4
- WS/URC Sldg Tks:
Person-Rem
- 0.303
- 8.636- :
- 4.657
- 4.058
- 17.654:
Person-Hours :
- 93.5
120 :
- 242.5
..............__________.. __.. _____ ________...____...... __..__......._____.__
- TOTALS:
Person-Rem
- 0.268
- 0.447
- 9.474
- 4,239
- 5.1350 : 4.058
- 25.621:
Person-Hours :-
18 : 2.4
- 100.5
135
122 :
28 : 405.9 :
,
. - -.. -.. -... - - - - - - - -.