ML16341E853
| ML16341E853 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 10/31/1988 |
| From: | North H, Tenbrook W NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | |
| Shared Package | |
| ML16341E854 | List: |
| References | |
| 50-275-88-27, 50-323-88-25, IEIN-83-33, NUDOCS 8811160184 | |
| Download: ML16341E853 (12) | |
See also: IR 05000275/1988027
Text
U.
S.
NUCLEAR REGULATORY COMMISSION
REGION V
Report Nos.
50-275/88-27
and 50-323/88-25
License
Nos.
DPR-80 and
Licensee:
Pacific Gas
and Electric Company
77 Beale Street
Suite 1451
San Francisco,
California 94106
Facility Name:
Diablo Canyon
Power Plant - Units 1 and
2
Inspection at:
Diablo Canyon Site - Seven Miles North of Avila Beach,
Inspection
Conducted:
October 3-7,
1988
Inspected
by:
W.
K. TenBrook, Radiation Specialist
/o/M/$$
'ate
Signed
Approved by:
H.
S. North, Acting Chief
Faci 1 ities
Radi ol ogi cal Protecti on Section
Date
igned
~Summa m
chemistry activities, water
chemistry control, chemical
and radiochemical
analyses,
and onsite follow-up of inspector-identified
items.
Inspection
procedures
30703,
84750
and 92701 were addressed.
Results:
Strengths
were observed in the following areas:
Control of ionic
impurities in the secondary
system,
improvement of water chemistry regimes for
primary and secondary
systems.
Weaknesses
were observed in condensate
dissolved
oxygen control
and timeliness of actions
by gA and chemistry
departments
pursuant to audit findings.
Overall, the licensee's
chemistry
program performance
was satisfactory in accomplishing
tasks
important to
safety.
8811160184
881031
ADOCK 05OOOP75
G
PNU
0
DETAILS
Persons
Contacted
Licensee
P. Baxter, Instructor, Technical
8 Maintenance Training
- J. Boots,
Manager,
Chemistry
K. Cortese,
Chemistry
Foreman
"K. Doss,
Senior Engineer; Onsite Safety Review Group
- C. Eldridge,
Manager, quality Control
"J. Gardner,
Senior Engineer,
Chemistry
- J. Gisclon, Assistant Plant Manager,
Support Services
L. Goyett,
Engineer,
Onsite Engineering
F. Guerra,
Radiochemistry
Foreman
"R. Harris, Supervisor, guality Assurance
Audits
R. Johnson,
General
Chemistry
Foreman
"W. Kelly, Engineer,
Regulatory Compliance
M. Leppke, Onsite Project Engineer
"J. Shoulders,
Assistant Onsite Project Engineer
'"D. Taggart, Director, guality Support
H. Thailer,
Lead Engineer,
Corporate
Engineering
E. Wessel,
Chemical
Engineer
- L. Womack, Assistant Plant Manager,
Operations
Contractor
J. Bellows, guality Assurance
Consultant,
Cygna
P. Narbut, Senior Resident Inspector,
Diablo Canyon
Fol 1 ow-u
(92701
0 en Item 50-275/87-24"Ol
OPEN
This item concerned
the clarification
of criteria for decisions
to repair secondary piping thinned by
erosion/corrosion.
The licensee
had not addressed
this issue, citing a
lack of reliable pipe wall thinning data
and the absence
of
widely-accepted criteria for repair and replacement
decisions.
During
the interim, the licensee relied upon case-by-case
evaluations
to make
pipe repair and replacement
decisions.
The licensee
stated that an
Engineering Instruction addressing
pipe repair and replacement
decisions
would be issued following Unit 2 piping inspections
and the March 1989
meeting of the Erosion/Corrosion
Task Force.
The licensee
agreed to
supply
a written commitment describing the timetable for issuance
of the
Engineering Instruction.
This item will remain
open pending
NRC review
of the Engineering Instruction regarding pipe repair, and replacement
decisions.
0
A.
Water Chemistr
and Radiochemical
Anal sis
84750
The inspector
reviewed the involvement of the licensee's
guality
Assurance
and guality Control organizations
in the chemistry
and
radiochemistry
areas
pursuant to 10 CFR 50, Appendix
B and ANSI-N18. 7.
The last programmatic audit covering these
areas
was documented
in audit
report 87093T,
dated July 30, 1987, which fell within the designated
two
year audit cycle.
One Audit Finding Report,
AFR 87-126,
stated that
quality-related
and safety-related
chemistry activities
had not been
defined pursuant to administrative procedures.
The licensee
had deliberated
over this audit finding for fifteen months
without resolution.
The Chemistry Department
had been reluctant to
classify procedures
as safety-related
or quality-related
and hence
be
required to revise the designated
procedures
to comply with the
gA
Manual, insisting that certain
gA Manual requirements
were inappropriate
for nuclear chemistry activities.
As an alternative,
the Chemistry
Department
had drafted
a gA Manual procedure
intended to guide auditing
personnel
in evaluating chemistry activities.
During the inspection,
negotiations
were proceeding
between guality Assurance
and Chemistry
on
defining safety-related
chemistry procedures
versus
the acceptability of
the draft gA manual
procedure
on chemistry.
The inspector also reviewed
a sample of guality Assurance
technical
specification surveillance
reports
and guality Control surveillance
reports for the period January
1988 to the date of the inspection.
No
technical specification
(TS) noncompliance
was identified within the
sample.
guality Control surveillance
88-39 identified problems involving
attention to detail during Reactor Coolant System
analyses.
These
problems
appeared
unrelated to other difficulties in
hydrogen control described
in Section 2.B., below.
The licensee
also
addressed
INPO findings in the
gC surveillance
program.
The involvement of guality Assurance
and guality Control in the chemistry
area
has
been satisfactory.
However,
some outstanding
gA findings had
not been expeditiously resolved.
The Chemistry and
gA
Departments'nability
to reach
a satisfactory
compromise with regard to gA
requirements
in the chemistry area
suggests
a weakness
in the licensee's
ability to promptly integrate specialized plant activities into their
overall
gA oversight program.
B.
Water Chemistr
Control
and Anal sis
The inspector
reviewed monthly reports of chemistry data,
laboratory
logs,
and observed
instrument indications during tours to assess
overall
chemistry performance with respect to the technical specifications,
and vendor guidelines,
and licensee
procedures.
RCS ionic impurities were held well below action levels,
and chloride
levels were particularly low.
TS fluoride levels were not
approached,
but occasionally
appeared
in chemistry data at levels below
0
the 50 ppb detection limit f'r the specific ion electrode
method
employed.
The licensee
had identified continuing problems involving RCS hydrogen
control.
The inspector
noted that the licensee's
target control
band of
30-40 cc/kg
RCS dissolved
hydrogen is relatively restrictive,
and
approximated
the
recommended
25-35 cc/kg for alloy 600 steam
generator
tubes.
Over the past year, operating unit RCS hydrogen levels
were out of the procedural
control
band from 10K to 30K of the time.
To
improve hydrogen control, the licensee
had decreased
the high pressure
alarm setpoint
on the volume control tank (VCT) and incr eased
addition regulator settings,
as well as improving communications
between
operations
and chemistry.
The inspector
observed that Unit 1 operating
'hydrogen levels were generally within the control
band the month prior to
the inspection, exhibiting improved performance.
Corrective actions for
Unit 2 were to be completed prior to startup.
Licensee
procedure
OP F-5: I, "..
~ Control Limits and Action Guidelines for
Primary Systems...,"
contained
a new lithium/boron coordinated
chemistry,
which provided
an
pH increase
from 6.9 to 7.5 during the middle and
later portions of the operating cycle.
This
pH regime would decrease
deposition rates of corrosion products
on
RCS surfaces,
hence decreasing
radiation
dose rates in and around
RCS components.
The inspector
noted that the licensee's
coordinated
concentration
band at the beginning of the. cycle did not provide for a
pH of 6.9 or above,
as
recommended
in the
EPRI Primary Water
Chemistry Guidelines.
The inspector
reviewed
a letter
from the
licensee's
reactor/fuel
vendor,
dated August 2, 1988, which contained the
approved lithium control program.
The program specified
a pH lower than
6.9 prior to constant lithium operation in order to conservatively
decrease
the risk of primary water stress
corrosion cracking
(PWSCC)
due
to sustained
high
Ionic impurities in secondary
water systems
had generally decreased,
in
terms of ppb-days'eriodic
excursions of sulphate
and sodium were
observed
in condensate
polisher discharge
and steam generator
blowdown,
associated
with operating transients.
The excursions
were generally
attributed to polisher operation
and reappearance
of hide-out from
previous polisher impurity ingress.
Concentrations
greater
than action
level
one were corrected within one week of diagnosis,
per procedure
OP
F-5: II, "Chemistry...Action Guidelines for Secondary
Systems".
Condensate
dissolved
oxygen frequently exceeded
action levels.
This
condition had been attributed to condensate
system inleakage,
and the
licensee
had taken appropriate
steps
to identify such leakage.
However,
recent contractor studies
suggested
that the condenser air removal
system
was inefficient, allowing significant dissolved
oxygen concentrations
to
remain in the condensate.
Preliminary results
indicated that the
inefficiency was caused
by fouling of the condenser
near the air
ejectors,
causing air binding, high and uneven hotwell water level,
inappropriate location of condensate
polisher recycle line discharge,
and
low-biased instrument indications of offgas flow rate.
The inspector
will examine the licensee's
actions to improve condensate
dissolved
oxygen performance
during a future inspection
(50-275/88-27-01).
The licensee
had initiated a boric aci'd addition program for secondary
water at the request of their,steam generator
vendor.
The boric acid
addition is intended to prevent tube denting by borate intrusion into
crevices
and pores,
passivating
the surface,
and thereby preventing
attack by other chemical
species.
Secondary water chemistry effects were
generally subtle,
except for a changed relationship
between specific
conductivity and
ammonia concentration.
The inspector calculated
the
peak boron injection rate
as approximately equivalent to the boron
ingress to the steam generators
resulting from the
TS identified leakage
limit, 10 gpm, at 1000
ppm boron operation.
Given the low boron
concentrations
involved, the process
did not appear to impair any'afety
systems
or place
systems
in an unanalyzed
condition.,
The inspector frequently toured the primary and secondary
system
laboratories
and the condensate
polisher
rooms during the inspection.
The secondary
water chemistry laboratory
was
a significant addition to
chemistry facilities.
The inspector
observed that housekeeping
in the
primary water laboratory
had improved since previous inspections,
as the
new laboratory performed
much of the secondary
system analytical
workload.
Fume
hood flow and
maximum sash
openings
were uniformly
established,
but some secondary
lab hood sashes
were left wider than
maximum.
No wet chemistry activities were observed
in hoods
opened
beyond
maximum.
Coats
and safety glasses
were worn within all
laboratories.
A precautionary frisk was required to exit the secondary
lab, located outside the controlled area
boundary.
The inspector
examined the instrumental
control program for water
chemistry analyses.
RCS fluoride, by the specific ion electrode
method,
had exhibited
some off-normal behavior with independent
control standards
at 20 ppb, which was at or beyond the sensitivity of the technique.
Control standard
concentration
was changed to 100 ppb, which was within
the capabilities
of the method,
and response
was
improved.
Also, the
licensee
now considers
instrumental
systematic
bias in control chart
evaluation
by identifying seven consecutive
control points
above or below
the
mean
as
a bias trend.
The inspector
reviewed the results of chemical analysis
intercomparisons
conducted
using spiked samples
from a vendor laboratory.
Poor results
were obtained for the intercomparison of a secondary
water matrix sample
containing
20 ppb fluoride.
The licensee
did not routinely perform
fluoride analysis for secondary water,
and the specific ion electrode
(SIE) method
was routinely used for RCS fluoride.
The poor
intercomparison
results reflected the 50 ppb fluoride detection limit by
SIE.
Although it was agreed that SIE was acceptable
for routine
fluoride, the licensee
stated it was their intention to use ion
chromatography to improve the accuracy
and sensitivity of routine
fluoride analyses.
The licensee
had implemented
a superior program for control of primary
and secondary
water chemistry, chiefly by the prompt implementation of
improved
RCS coordinated
chemistry,
boron passivation
for steam
0
generators,
and incremental
reduction of secondary
water impurities.
Weak areas
remained in condensate
oxygen control,
and the improving
effectiveness
Radiochemical
Anal sis
The inspector
reviewed the licensees
procedures
and practices for
sampling
and analysis of waste oil and other mixtures.
Procedure
D-611, "...Release
of...Sludges,
Slurries
and Oils from the
RCA,"
instructed radiation protection personnel
to mix these
wastes
thoroughly,
but also cautioned
the reader to take samples of each
phase
when mixing
was not achievable.
Criteria for unconditional
release
were less
than
0.1 pCi/ml
gamma activity, less
than
1000 pCi/ml tritium, and
administrative
approvals.
The procedure
addressed
NRC Information Notice
IN-83-33, "Nonrepresentative
Sampling of Contaminated Oils."
The inspector verified that adequate
measurement
control checks
were
performed for radioanalytical
instruments
per procedures
and industry
standard practices.
Areas for improvement regarding width of control
limits were being addressed
in response
to recent
independent
audit
findings.
The inspector
conducted tours of the 85'levation of the Auxiliary
Building, principally to observe
operation of the Unit One Post Accident
Sampling System
(PASS).
Area radiation monitors
and air monitors were
observed to be within their calibration dates,
and postings
were properly
maintained.
The inspector
observed
and containment
atmosphere
sampling using the
PASS during a training exercise.
concentrations
obtained
by the carminic acid method in the
laboratory were in excellent
agreement
with routine measurements.
The
Inspector also reviewed attachments
to Surveillance Test Procedure
G-14 which contained
intercomparisons
for all measurements
required
by
NUREG-0737, II.B.3. for the period January to June
1988.
Intercomparison
with routine measurements
indicated that representative
samples
and
accurate
measurements
were obtained using
PASS equipment for those
concentrations
observable with PASS lab techniques.
The licensee's
program for radiochemical
measurements
was satisfactory.
Procedures
for sampling two-phase mixtures were considered
superior,
given that personnel
properly follow instructions for sampling each
phase
as necessary.
Exit Meetin
30703
The Inspector
met with licensee
management
on October 7, 1988, to discuss
the scope
and findings of the inspection.
The inspector
recognized that-
the resolution of AFR 87-126 remained subject to continued internal
negotiation.
However, the inspector also stated that programmatic audits
of the chemistry program were expected to be performed
as required,
and
should not to be delayed contingent
on the resolution of past audit
findings, including AFR 87-126.
The inspector
also confirmed that the
licensee
would prepare
and submit
a written commitment containing
a
schedule
for issuance
of a pipe repair/replacement
decision instruction.