ML20215C765
| ML20215C765 | |
| Person / Time | |
|---|---|
| Site: | Crystal River  |
| Issue date: | 09/29/1986 |
| From: | Walker R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | Wilgus W FLORIDA POWER CORP. |
| References | |
| NUDOCS 8610100433 | |
| Download: ML20215C765 (10) | |
See also: IR 05000302/1986006
Text
-
,
Or/hN)al
1
1.
SEP 2 91986
Docket No. 50-302
License No. DPR-72
/ Florida Power Corporation
ATTN: Mr. W. S. Wilgus
Vice President Nuclear Operations
P. O. Box 14042, M.A.C. C-2-M
St. Petersburg, FL 33733
Gentlemen:
SUBJECT:
NRC INSPECTION REPORT N0. 50-302/86-06
Our letter dated May 13, 1986, in response to your letter of April 24, 1986,
stated that we were eva!uating your response to the Notice of Violation
transmitted with Inspection Report No. 50-302/86-06, and that we would notify you
of the acceptability of your response in the near future.
Your response to Violation 1 has been found to be acceptable and we will evaluate
the implementation of your corrective actions during future inspections.
After careful consideration of the basis for your denial of Violation 2, we have
concluded for the reasons given in Enclosure 1 to this letter, that the violation
occurred as stated in the Notice of Violation. Therefore, in accordance with the
requirements of 10 CFR 2.201, please submit to this Office within 30 dais of the
date of this letter, a written statement describing steps which have been taken
to correct Violation 2 and the results achieved, corrective actions which will be
taken to avoid further violations, and the date when full compliance will be
achieved.
You stated in your April 24, 1986, letter that Inspection Report No. 50-302/86-06
did not recognize efforts by FPC to demonstrate that " reasonable assurance"
already existed or FPC's objections to the apparent violation. Your attention is
invited to Enclosure 2 of this letter which details the NRC position on this
matter.
The responses directed by this letter and the enclosures are not subject to the
clearance procedures of the Office of Management and Budget issued under the
Paperwork Reduction Act of 1980, PL 96-511.
.
G
1\\
hN
.
t
.
Florida Power Corporation
2
We appreciate your cooperation in this matter.
Sincerely,
Original Signed by
Roger D. Walker
Roger D. Walker, Director
Division of Reactor Projects
1
Enclosures:
1.
Staff Assessment of Licensee
Response
2.
Staff Assessment of Licensee
Letter Transmitting Licensee
Response to Inspection Report
No. 50-302/86-06
/ccw/encls:
P. F. McKee, Director, Nuclear Plant
/R. C. Widell, Manager Nuclear Operations
Operations
Licensing and Fuel Management
bec w/encls:
4RC Resident Inspector
Document Control Desk
State of Florida
)Q
h&
J. bw/#"
,
/3E/(
9lF1lN
R11
JPStohr
9/ /86
j gg
jh
h+a
N
.
BRevsin
CHqsey
DCollins
SElrod
DVerrelli
GJenk %s
9/l$/86
9/ /86
9/7[/86
9/2f/86
9/%/86
9/yB6
,
'
RII
JSt ahr
9/p%86
_
_ .
. _ .
__
__ _.
_
_ - . _ . _ - _ _ - - - - - - - -
- - _ - - - - - -
- . - _
___
. _ . _
_
- - _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ - _ _ _ _ _ _ _ _ _ _
.-
.-
ENCLOSURE 1
STAFF ASSESSMENT OF LICENSEE RESPONSE TO
.
Violation 50-302/86-06-02, failure to provide reasonable assurance that the
radionuclide distribution of dry active waste could be correlated to actual
measurements of reactor coolant.
1.
Licensee Comment
FPC's program for classifying wastes includes a proceduralized method for
determining radionuclide concentrations on dry active waste (DAW) by use of
scaling factors for those nuclides which cannot be readily measured.
NRC Response
At the time of the inspection, Procedure WP-101, " Packaging, Storing, and
Shipping of Radioactive Materials," Revision 10, November 25, 1985, was
reviewed.
Enclosure 13 of the procedure, " Methods for Determining Curie
Content," specified that the isotopes Tc-99, I-129, Transuranics (TRU),
Pu-241 and Cm-242 were to be calculated using correlation factors (scaling
factors) to Cs-137 obtained from a vendor document dated 11/83 or from the
Isoscale computer code.
As referenced in the Inspection Report
No. 50-302/86-06, the licensee was not in compliance with their procedure
in that scaling factors used for determining the concentrations of the above
listed isotopes were not drawn from either of the two sources required by
Procedure WP-101.
In addition, the licensee was not scaling the above
listed isotopes to cesium-137 as required by WP-101.
Consequently, at the
time of the inspection, the licensee was not following the instructions
contained in Procedure WP-101, and, consequently did not have a
proceduralized method in place for determining radionuclide concentrations
on dry active waste by use of scaling factors for nuclides that cannot be
readily measured.
l
2.
Licensee Comment
Concisely, the classification method relies on direct measurement of
composite samples obtained from the primary source of radioactivity which
contaminates dry waste,
i.e., the Reactor Coolant System (RCS) which is
permitted by the NRC's technical position paper which states that an
estimate of the radionuclide distribution within waste could be made based
I
upon distribution determined from other waste streams associated with the
generation of trash.
NRC Response
10 CFR 61.55(a)(8) permits the indirect determination of concentrations of
difficult to measure radionuclides by use of scaling factors which relate
the inferred concentration of one radionuclide to another that is measured
_ _ _ _ _ _ _ _ _ _ _ _
.-
-
.
Enclosure 1
2
provided there is reasonable assurance that the indirect methods can be
correlated with actual measurements.
In general, licensees have demonstrated the relationship of inferred
radionuclide concentrations to actual measurements by either directly
sampling the waste stream that is to be classified or by sampling waste
during a stage of generation that is directly related to the final physical
form of the waste that is to be classified.
This is in agreement with the
NRC technical position paper, Paragraph 2, which states that samples may be
taken for analysis either from the final waste form or from the waste prior
to processing into a final waste form.
Samples taken prior to final
processing should enable the results of the sample analysis to be directly
translated to the final waste form.
Thus, FPC's practice of using reactor
coolant radionuclide distributions to develop scaling factors for inferring
.
concentrations of difficult to measure isotopes in DAW would be
inappropriate without an evaluation based on actual plant data that
demonstrated that DAW and reactor coolant had similar radionuclide
distributions.
The licensee had not, at the time of the inspection,
determined that reactor coolant and DAW had similar radionuclide
distributions. Subsequent to the inspection, the licensee performed such an
evaluation for cobalt-60 and cesium-137 and concluded that there was
adequate correlation (see Item 10).
This evaluation is one element
necessary for adequate corrective action, but should have been done prior to
concluding that there was correlation between waste streams.
3.
Licensee Comment
Attachment 1 Waste Scaling Program Description, states that at the start of
the program in September,1982, the Nuclear Waste Manager and Supervisor
identified four major waste streams of which Dry Active Waste (DAW) was one.
In studying the contaminated areas in the plant and the source of the
contamination, the following logic was formulated for using scaling factors
which are based on fluid system samples:
,
a.
All contaminated leakage is from the RCS.
b.
To contaminate an area, the RCS is deposited on floor, walls,
j
equipment, etc.
c.
When the water evaporates, all isotopes except H-3 are left on the
contaminated area.
d.
When an area is decontaminated, the isotopes are removed to the floor
,
drain and transported to the miscellaneous waste storage tank (MWST).
l
t
e.
When another leak occurs, the isotopes mix and either dry in place or
migrate to the floor drain.
!
,
i
. . _ . - - -
--
-,.
.,.
-
,
, - - --
..
.-
Enclosure 1
3
f.
In the case of an area that stays contaminated, it is either because:
(1) The area is not frequently traveled and does not contribute more
that 1 to 2% of the total DAW compacted in each drum.
(2) There is a leak continuously flowing to the floor drain and the
area cannot be decontaminated until the leak is fixed.
(3) The area is in a high traffic flow and can only be decontaminated
periodically.
This periodic waste is disposed of in the floor
drain.
In the case of an area that is only contaminated for a short period of
g.
time, the decon waste is disposed of in the floor drain.
h.
The waste generated during the sampling and analysis of contaminated
systems is drained to the MWST.
i.
In addition to the floor drains, the MWST also collects drainage from
equipment, such as pumps, which are also source of DAW due to
maintenance activities.
NRC Response
We concur that RCS is the source term for contaminated liquid that may
a.
<
eventually be expressed as leakage within the plant.
However, we do
not concur that all leakage is from the RCS.
Leakage originates from
many sources (systems and equipment) throughout the facility, and in
consequence, has been subjected to numerous processes, both chemical
and physical, which have the potential to affect radionuclide
concentrations at a particular point or component as well as the ratios
of the various radionuclides to one another.
Different systems, and
pieces of equipment within systems, will sequester radionuclides from
reactor coolant by different mechanisms which are themselves subject to
'
change depending on such factors as plant chemistry, filter loading,
physical perturbations in the plant, etc. Consequently, while the RCS
may act as the source term for plant leakage, all plant leakage will
not be the same, nor will it be the same as reactor coolant.
While leakage may constitute the majority of the plant's liquid
radioactive waste, we do not concur that leakage cleanup generates the
major portion of DAW shipped from reactor facilities. DAW is composed
primarily of paper, plastic, and cloth generated during normal
maintenance activities during routine plant operation, but the majority
of DAW is generated during refueling outages and its associated
activities and special maintenance.
During these activities, system
contamination, which will possess differing radionuclide distributions
depending on its system of origin, is spread to protective clothing,
plastic, herculite, etc., primarily by the process of friction, i.e.,
rubbing against a contaminated component.
While the removal
efficiencies for the various radionuclides may differ depending on the
- ..
-
- ,_.
- .-
. _ - -
-
-__ __
_
- _ - . .
.
_
_
___
-.
. _ . _
. _
. _ _
_ . _ _
f
.-
.-
Enclosure 1
4
,
i
material involved, the acquisition of contamination on the material
_ generally occurs through a physical process rather than relying upon
,
the selective solubilities of the various radionuclides in liquid as is
'
the case for MWST or reactor coolant.
Consequently, sampling MWST or
reactor coolant with the objective of developing scaling factors for
,
use in classification of DAW would be. inappropriate unless there was an
evaluation based on actual plant data which demonstrated that reactor
coolant, MWST, and DAW have similar radionuclide distributions.
4.
Licensee Comment
!
l
The method of smearing the building and using this as a sample was not
!
used since as stated in the Federal Register, a smear only removes
about 10% of the fixed contamination.
,
NRC Response
It is unlikely that smearing will remove any of the fixed contamination
since by definition if the contamination is fixed, it would not be
i
l
removed by smearing. Additionally, the efficiency achieved through the
!
smearing process is not a critical factor in this instance since the
l
information being sought is the radionuclide. ratios rather than
i
absolute concentrations.
5.
Licensee Comment
When analyzing the smears at the offsite lab, a quantity of 30 or more
smears interferes with several of the analyses being performed.
l
NRC Response
While it is easier and more convenient to analyze liquid rather than
i
i
composite smear samples, as long as appropriate geometries and quality
l
controls have been established, composite smear samples can be handled
l
with acceptable accuracy. Composite analyses of smears and filters has
!
long been .an established and accepted industry practice and are
routinely performed by numerous laboratories.
!
l
6.
Licensee Consnent
i
l
The composite of smears does not take into account the activities in
j
the building and due to the limited number of smears taken, a composite
over the quarter is not possible as is with the MWST.
NRC Response
l
There is no limit to the number of smears or composite smear samples
i
that may be taken, the acquisition of which should take into account
i
the activities in the facility so that the waste stream will be
l
adequately characterized.
!
1
!
, - , .
. - , _
- - _ , . . - - - _ , _ , , - -
--.
-
.-
.-
Enclosure 1
5
7.
Licensee Comment
The smear is technician dependent due to unavoidable effects of the
area of the smear, pressure applied to the smear and accessibility of
the area.
NRC Response
The surface textures being smeared as well as the pressure applied to
the smear are factors known to effect smear removal efficiencies and
are factors that effect the transfer of radionuclides to DAW as well.
It is reasonable to assume that an average approximation is achieved by
the smearing process.
As to the accessibility of the area, if it is
inaccessible to the point to limiting smearing activity, then it is
unlikely that is is an area that contributes greatly to the generation
of DAW.
8.
Licensee Comment
Isotope distributions from smear sampling of plant areas do not
necessarily duplicate the isotopes found on DAW due to differences in
selective adsorption or absorption of smear material versus that of the
'
plastics, clothing, rubber, Herculite, paper, wcod, etc., that make up
DAW.
NRC Response
While smear sampling suffers from the limitations described, the
similarity of smears to DAW is likely greater than that of DAW to a
liquid sample, either reactor coolant or MWST, and in addition, they
have the added benefit of being more related to the waste form being
shipped.
9.
Licensee Comment
The composite of the MWST is a better representation of Crystal River
DAW over the total period that the waste is generated. The use of the
reactor coolant system numbers in place of MWST correlation numbers was
due to the similarity of the two waste streams as stated in the
independent verification of Crystal River's " DAW Scaling Factors for
10 CFR 61" and is considered a conservative method of operation without
overestimating the curie content of the difficult to measure isotopes.
NRC Response
Inspection of the ratios of the MWST and reactor coolant scaling
factors for the third quarter 1985, as presented in Table 2,
Attachment 2, demonstrated that these ratios are in agreement by a
factor of ten for all nuclide ratios except Pu-241/PU-239.
Agreement
between these two sample types indicate that reactor coolant and MWST
samples are similar in their radionuclide distributions and that either
set of scaling factors may be used to infer concentrations of difficult
_ _ _ _
_.
_.
_.
_ _ _ _ _ _ _ _
_.
__
_ .
_ _ - . _
.-
.
Enclosure 1-
6
to measure radionuclides for purposes of classifying waste from either
of these two waste streams.
However, there is no evidence to suggest
that scaling factors developed from either of these waste streaus is
representative of DAW.
10. Licensee Comment
The direct, nondestructive measurement of the activity ratios of
cobalt-60 to cesium-137 in individual containers of DAW can be used to
evaluate the representativeness of the sampling approach.
By using
this ratio, variations in levels of activity can be normalized.
Table 3 shows this ratio for the samples sent offsite for analysis, for
five actual drums of waste measured onsite and for a composite of
smears taken from various controlled areas.
The geometric means from
these data sets (drums, RCS, and MWST ) and the single result from the
smears all agree within a factor of ten.
This establishes that DAW
scaling factors based on either RCS or MWST samples are adequately
correlated with actual DAW activities.
NRC Response
A.
At the time of the inspection, the data in Table 3, namely
cobalt-60 and cesium-137 concentrations for in situ waste drums
and for smears, were unavailable for reviewly the inspector.
Even so, the significance of these data is unclear.
Performing
gamma isotopic analyses on samples of MWST, reactor coolant, drums
of DAW and plant smears and obtaining activity ratios of cobalt-60
and cesium-137 so as to normalize the activities observed and then
comparing the geometric means of such ratios requires that certain
assumptions be made, namely, that there is a relationship between
the amount of cobalt-60 and cesium-137, or activation products and
fission products, within the plant, and that this relationship is
constant. This would mean that:
(a) the relationship would not be affected by component or system
of origin within the plant
(b) cobalt-60 and cesium-137 tranport patterns within the RCS
would describe a constant relationship
(c)
the removal efficiencies for cobalt-60 and cesium-137 by
various components in the plant would describe a constant
relationship
(d) changes in system chemistry would effect cobalt-60 and
cesium-137 similarly so as to maintain a constant ratio
(e) physical perturbations due to plant operations would affect
cobalt-60 and cesium-137 similarly, and
- - _
_ . - .
.
_ _ _ _ _ _ _
_
_ _ . _ .
_ _ _ _ _
.-
-
.
Enclosure 1
7
.
(f) the rate of release of cesium-137 from fuel pellets and the
activation of cobalt to cobalt-60 in the plant would describe
a constant ratio.
None of the above are known to be true.
In fact, the available
evidence suggests that the use of such assumptions leads to the
,
generation of. generic scaling factors without waste stream
>
specificity.
Based on the guidance provided by the 1983 NRC
technical position paper, this is an unacceptable practice.
B.
An area of concern overlooked by the licensee's methodology is
that of the non gamma-emitting nuclides,
i.e.,
Sr-90 and
transuranic radionuclides.
Recently published studies in
NUREG/CR-4101, " Assay of Long-Lived Radionuclides in Low-Level
Wastes from Power Reactors," have shown large uncertainties
associated with the ev.tracted scaling factors for Sr-90 and Cs-137
in reactor coolant cue to differences in chemical behavior of
these two radionuclides.
In the range of cesium-117
concentrations commonly found in DAW (10-2 to 10-4 microcuries per
cubic centimeter), it was found that concentrations of Sr-90 can
be underestimated by factors of seven to 250. These uncertainties
were considerably minimized by performing waste stream specific
analyses.
Consequently, extrapolation of reactor coolant or MWST
scaling factors for Sr-90/Cs-137 without e;opirical verification of
the appropriateness of such a step may lead to a nonconservative
determination of Sr-90 for DAW which may be significant for
purposes of classification.
Conclusion
The licensee did not provide reasonable assurance that the indirect
methods used for inferring the concentration of one radionuclide to
another that is measured for DAW could be correlated with actual
measurements in that they failed to determine that the radionuclide
distributions of DAW and reactor coolant and/or MWST were similar.
Therefore, it is our position that the violation did in fact, occur.
,
t
i
~
,
- . . . - . -
. . -
-
,
- -
- - , , _ , . . . - . ~ - . - , - . - , . _ , . _ . . - .
.
-
-.
_
_
_ _ .
__
_ _ . _ _
_
- _ . _
__
4
-
.
.
i
I:
~
ENCLOSURE 2
STAFF ASSESSMENT OF LICENSEE LETTER TRANSMITTING
LICENSEE RESPONSE TO INSPECTION REPORT NO. 50-302/86-06
i
Licensee Comment
The inspection report in describing the exit interview, stated that "The licensee
acknowledged the inspection finding and took no exceptions."
FPC is providing
- this information to assure that the record is complete regarding proposed
i
Violation 86-06-02.
During the inspection and the informal inspection exit, FPC
personnel discussed with the inspector the rationale for choosing this scaling
method for DAW, and the work that had been done and that was ongoing to verify
!
-
our correlations.
During the informal exit, FPC took exception to this
violation.
On two occasions subsequent to the inspection, once via telecon and
-
once in person, FPC initiated similar discussions with Region II inspection staff
,
on this apparent violation and suggested that it was not a violation but more
'
appropriately an inspector follow-up or unresolved item.
The inspection report
i
does not recognize these efforts by FPC to demonstrate that " reasonable-
- assurance" already exists or FPC's objections.
'
NRC Response
At the exit interview held on January 31, 1986, senior management representatives
present did not take exception or state objection to the findings that were
presented.
We acknowledge that the issue in question was discussed prior to and
j
on occasions subsequent to the formal exit; however, at no time did FPC
representatives categorically state an exception to the findings. - Findings
presented during an exit interview are preliminary in nature, and before they are
,
officially transmitted to the licensee, they are reviewed, evaluated and approved
i
by Regional management.
Had the licensee indicated an exception to the findings
-
j
at the exit interview, this would have been considered by Regional management
!
prior to issuance of the inspection report. Since licensee management present at
'
l
the exit interview did not register an exception, the NRC considers that the
inspection report is accurate as stated.
,
Evaluation of licensee practices at the time of the inspection indicated that the
licensee did not have " reasonable assurance" as the licensee suggested, and
'
consequently, a violation of regulatory requirements was considered to have
occurred.
As such, the issuance of a Notice of Violation in accordance with
10 CFR 2 was determined to be apprcpriate.
-
!
!,
d
l
1
!
!
-. . . - - - -
- . - -
_
- - - - - . .
_ . _ , ,
,. - - _ ~.- - -
. , _ _ .