ML20212P228
| ML20212P228 | |
| Person / Time | |
|---|---|
| Site: | Crystal River  |
| Issue date: | 08/15/1986 |
| From: | Elrod S, Stetka T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML20212P217 | List: |
| References | |
| 50-302-86-22, NUDOCS 8609030040 | |
| Download: ML20212P228 (8) | |
See also: IR 05000302/1986022
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[A Hig
UNIT E") STATES
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NUCLEAR REGULATORY COMMISSION
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REGION 11
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101 MARIETTA STREET,N.W.
ATLANTA, GEORGI A 30323
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Report No.:
50-302/86-22
Licensee:
Florida Power Corporation
3201 34th Street, South
St. Petersburg, FL 33733
Docket No.:
50-302
License No.:
Facility Name:
Crystal River 3
Inspecticn Con ucted:
une 18-20, 1986 and July 9, 1986
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Inspector:
/M/14dl0)
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g/r/er, -
E F. St dka~, Senior Resident Inspector,
Date ' Signed
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Accompanying Personnel:
J. E. Tedrow, Resident' Inspector
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Ros'sh Reactor _Inspactor, Region II
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Approved by:
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S. Af ETrod, Section Chief
,Date Signed
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Division of Reactor Projects
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SUMMARY
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Scope:
This routine inspection was conducted by two resident' inspectors and one
regional inspector to review and observe waste gas decay tank.(WGDT) operations.
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An Enforcement Conference was held on July 9,1986 at the licensee's corporate
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office in St. Petersburg, Florida.
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Results:
Two violations were identified: (Failure to isolate WGDT's and provide
timely reductions of oxygen concentrations in these tanks, paragraph 6.c.1;
Failure to provide adequate corrective actions, paragraph 6.c.2).
8609030040 860020
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ADOCK 05000302
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REPORT DETAILS
1. Licensee Employees Contacted
- B. Hickle, Manager, Nuclear Plant Operations
- M. Mann, Nuclear Compliance Specialist
D. McCollough, Nuclear Chemistry Supervisor
P. McKee, Nuclear Plant Manager
- J. Roberts, Nuclear Chemistry Manager
- S. Robinson, Nuclear Waste Manager
V. Roppel, Manager, Nuclear Plant Techaical Support
- W. Rossfeld, Nuclear Compliance Manager
P. Skramstad, Nuclear Chemistry / Radiation
Protection Superintendent
- K. Wilson, Manager, Site Nuclear Licensing
Other personnel contacted included operations, engineering, and chemistry /
radiation protection personnel.
- Attended exit interview
2. Exit Interview
The inspector met with licensee representatives (denoted in paragraph 1) at
the conclusion of the inspection on June 20, 1986.
During this meeting the
inspectors summarized the scope and findings of the inspection with
particular emphasis on the tiolations as they are detailed in this report,
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The licensee representatives acknowledged the inspector's comments and did
not identify as proprietary any of the materials provided to or reviewed by
the inspectors during this inspection.
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3.
Licensee Action on Previous Inspection Iters
Not inspected at this time.
4.
Unresolved Items
No Unresolved Items are identified in this report.
5.
Enforcement Conference Held July 9, 1986.
a.
Licensee Attendees
W. S. Wilgus, Vice President - Nuclear Operations
P. F. McKee, Director - Nuclear Plant Operations
B. C. Simpson, Director - Nuclear Operations
Engineering and Licensing
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R. C. Widell, Manager, Nuclear Operations Licensing
and Fuel Management
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L. C. Kelly, Manager, Nuclear Operations Training
J. Alberdi, Manager, Nuclear Site Support
)
8. J. Hickle, Manager, Nuclear Plant Operations
b.
NRC Attendees
R. D. Walker, Acting Deputy NRC Region II (RII)
Administrator
L. A. Reyes, Acting Division Director, Division
of Reactor Projects (DRP), RII
S. A. Elrod, Section Chief, DRP, RII
T. F. Stetka, Senior Resident Inspector, Crystal River
J. E. Tedrow, Resident Inspector, Crystal River
c.
An Enforcement Conference was held July 9,1986 to discuss issues
related to repeated instances of inability to carry out the action
statements of Technical Specification 3.7.13.5 concerning potentially
explosive gas mixtures in the WGDTs.
Several corrective actions had
been seen the day before during a routine NRC management tour of the
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Crystal River facility.
During the conference, the licensee described
the waste gas system, the sequence of events and the corrective actions
being taken to improve operator response, surveillance procedures, and
the physical system.
The license's staff stated that while they
believed the issue involved the same technical specification, they also
believed that different issues were involved.
The NRC's concern was
that operator direction and response be appropriate to adequately
address the issue.
The NRC reserved judgment on the licensee's
position concerning " separate issues."
6.
Review of Waste Gas Decay Tank (WGDT) Operations
a.
Event Description
During a routine tour of the auxiliary building at approximately
6:15 a.m., on June 18, 1986, the inspector noticed unusual readings for
hydrogen (H ) and oxygen (0 ) concentrations on the Hays Analyzer
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2
Instrument Panel (Hays), which was monitoring the gas concentrations in
WGDT-1B.
The H2 channel was pegged high on the low (0-10%) scale and a
"High H " alarm was actuated on the panel.
It was further noted that
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the 0 channel was reading approximately 6% on the high (0-25%) scale
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and that no "High 0 " alarm was present.
The inspector realized that
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these readings (6% 02
and>10% H ) exceeded the maximum H2 and 0
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concentrations allowed in the WGDT's by the Technical Specifications
(TS) (TS 3.7.13.5 requires the 02 concentration in the WGDT to be less
than or equal to 2% whenever the H2 concentration is greater than or
equal to 4%).
f fter being notified of these observations, the
Auxiliary Nuclear Operator (ANO) verified the findings and contacted
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the Chemistry Department and the Assistant Nuclear Shift Supervisor
(ANSS) in the control room.
At 6:28 a.m. the ANO isolated WGDT-1B,
placed WGDT-1C in service, and requested chemistry personnel to obtain
a grab sample of WGDT-1B and analyze it for H2
2 to verify the
and 0
indications of the Hays analyzer.
The inspector observed sampling and analysis activities for the WGDT-1B
grab sample and discussed the results with the chemistry technicians.
When asked if the accuracy of the Hays analyzer was in doubt, chemistry
personnel indicated that the past operating history of the Hays
analyzer showed that it produced generally accurate results when
compared with grab samples.
The grab sample gas chromatograph analyses
were completed at approximately 7:35 a.m. and indicated that both the
H and 0 concentrations were greater than 4%, but the results did not
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agree with the values obtained from the Hays analyzer.
A second grab
sample was completed at approximately 8:15 a.m., and yielded results of
4.04% 0
and 5.64% H , which were consistent with the first grab
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sample.
This information was reported to the Nuclear Shift Supervisor
at 8:20 a.m. and Action Statement (b) of TS 3.7.13.5 was entered at
that time.
This Action Statement requires that whenever the
concentrations of 0
and H in a WGDT are greater than or equal to 4%,
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that additions of waste gas to the tank be immediately suspended and
the 0 concentration be reduced without delay.
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At approximately 9:30 a.m.
the inspector determined that no action had
been taken to reduce the 0 concentration in WGDT-1B. When the ANSS
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was contacted, he indicated that he doubted if sufficient nitrogen
(N ) was on site to dilute the 02 concentration in WGDT-1B and that the
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alternative of releasing the tank's contents to the environment was
being considered.
Meanwhile, at approximately 9:45 a.m., licensee personnel observed high
02 and H2 concentrations in WGDT-1C.
At 9:57 a.m. WGDT-1C was isolated
and WGDT-1A was placed in service.
A grab sample from WGDT-1C was
analyzed at 11:15 a.m. and indicated concentrations of 8.38% H and
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4.57% 0 ,
which provided good agreement with the Hays analyzer
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indications of 10% H and 4.5% 0 -
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The inspector then observed the licensee's efforts to reduce the 02 and
H
concentrations in WGDT-1B and WGDT-1C.
The AN0 experienced some
2difficulty in connecting a temporary N2 supply line to WGDT-1B.
The
threaded connection for this line had been damaged, preventing the
operator from tightening the fitting adequately.
The AND contacted the
control room for assistance, and pipe fitters were dispatched to repair
and connect the temporary N2 supply line.
This line was finally
connected to WGDT-1C and N
dilution of WGDT-1C was begun at
2
approximately 11:40 a.m.
Activities to reduce the 0 concentration in.
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WGDT-1B consisted of sampling the tank for radioactive nuclides and
preparing a radioactive gaseous release permit so that the tank could
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be released to the environment.
This process involved an approximately
5 hour5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> sample collection time followed by approximately 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> of
analysis time to generate the permit.
WGDT-1C was sampled again at 1:10 a.m. on June 19, 1986 and the gas
concentrations were determined to be within limits (02 - 1.83%, H2 -
3.19%).
After WGDT-1B was released, N2 was added to the tank and it
was sampled at 7:00 a.m. The gas concentrations were determined to also
be within limits (02 - 3.2%, H2 - 3.93%).
b.
Background Information
The inspector researched plant records to determine the cause of this
event.
Chemistry Department waste data sheets revealed that the
concentration of 0
in WGDT-1B had been greater that 4% since the tank
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was placed in service on June 14,1986, but H2 was less than 4%.
On
June 17, 1986, operations and chemistry personnel observed a hydrogen
pressure decrease in the Makeup Tank (MUT).
This H2 was thought to
have leaked out of the MUT through isolation valves to the waste gas
header from where it was introduced into WGDT-1B.
Plant personnel
monitor the concentiations of 02 and H2 in the WGDTs in accordance with
procedures WP-502 (Radioactive Waste Handling and Disposal Reporting),
and SP-300 (Operating Daily Surveillance Log).
Procedure SP-300 requires that each shift operators check to see if the
H and 0 channels of the Hays analyzer are in alarm.
In this event
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the 02 channel was not alarming since the high scale was selected
(meter deflection actuates the alarm).
This caused operators to
overlook the problem which existed with the 02 and H2 concentrations in
WGDT-1B.
Procedure WP-502 includes a data collection sheet which chemistry
technicians fill out daily.
On June 17, 1986, at approximately
11:37 p.m. the H2 and 02 concentrations in WGDT-1B were recorded on the
data sheets as 5.8% and 1.1% respectively.
The inspector discussed
these readings with the chemistry technician who recorded them.
Based
on this discussion and the trend of the 0 concentration since June 14,
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(the June 16, 1986 reading was 0.5% H2 and 7% 0 ) it appeared that the
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chemistry technician misread the scale for the 0
concentration on
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June 17, and that the actual 02 value was approximately 6% (the 1.1%
low scale reading coincides with 6% on the high scale).
TS 3.3.3.10 requires the licensee to have the capability to monitor H
and 0
inthethreeWGDTstopreventthebuildupofexplosivemixture$
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of these gases.
In addition, TS 3.7.13.5 requires that immediate
action be initiated to maintain the concentration of 0 2 in any WGDT
below 2% by volume whenever the concentration of H2 in the WGDT is
greater than or equal to 4% by volume.
These TSs were based on the
recognition that H2 is used throughout the reactor coolant system as a
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scavenger for dissolved 02 and also that the probability of inleakage
of air (20% 0 ) into the radwaste systems cannot be kept to zero.
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Consequently precautions must be taken to maintain concentrations of
these gases below the flammable or explosive limits.
The generally accepted guideline is that concentrations (by volume) of
0 and H equal to or greater than 5% and 4%, respectively, constitute
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a flammable mixture.
If the concentration of H is between 18.2% and
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58.9% and the concentration of 0
is equal to or greater than 5%,
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detonation can occur.
The methods of ignition are numerous because the
flammability limit is reduced as the temperature of the H2-02 mixture
increases.
Likewise, an increase in pressure of the H
-02 mixture
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decreases the minimum concentration of 02 required for flame
propagation.
The licensee has identified several sources of air inleakage (e.g. ,
compressor seals, waste evaporator, vacuum pump seals) that provide a
pathway for ingress of oxygen to the WGDTs.
The licensee attempts to
maintain the gas mixtures in the three WGDTs below the action levels of
TS 3.7.13.5 by normally aligning the MUT (the primary source of H )
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only to WGDT-1A.
The other two tanks, WGDT-1B and WGDT-1C, are used to
collect the noncondensible gases that are continuously being purged by
a nitrogen bubbler system from the various tanks in the Radwaste
System.
The high concentrations of 02 in WGDT-1B and WGDT-1C after June 14,
1986 were attributed to the fact that the reactor coolant bleed tanks
had been vented to the atmosphere while the plant was in cold shutdown
and had been only partially purged with N2 before being valved to
WGDT-18.
Although the subsequent leakage of H2 from the MUT may be
considered unusual, this event resulted in H - 0 mixtures in both
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WGDT-1B and WGDT-1C that exceeded the flammable limit and approached
the detonation limit in WGDT-1C on June 18, 1986.
The licensee states that two processes are available to reduce
potentially flammable or explosive H2 -02 mixtures; venting a WGDT or
diluting its contents with N .
According to the Nuclear Shift
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Supervisor's log, WGDT-1B was vented during the early hours of June 19,
1986 after the gases had been monitored for radionuclides.
When
WGDT-1B had been isolated at 6:28 a.m. on June 18, 1986, it contained a
gas mixture that was 4.07% 02
and 5.64% H .
Since the total gas
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pressure in this tank was about 20 psig, there was considerable room to
add dilution N .
The release of such a mixture without dilution with
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N
bordered on being hazardous because of the unknown factors
2associated with the effect of pressure and friction as sources of
ignition.
An analysis of the residual gas mixture in WGDT-1B at
7:00 a.m. on June 19, 1986, af ter this tank had been vented and then
pressurized with nitrogen, revealed that the gas mixture (3.2% 02
and
3.93% H ) was still close to the limit of TS 3.7.13.5.a.
At 2 p.m. on
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June 20, 1986 this mixture was observed to be 2% 02 and 3.2% H -
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When WGDT-1C was isolated at 9:57 a.m. on June 18 the analyses varied
but indicated that the concentrations of hydrogen and oxygen were 8-10%
and 4.6-5%, respectively.
This tank was pressurized with nitrogen
until the mixture was reduced to 3.19% H and 1.83% 0 - below the
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limit of TS 3.7.13.5.a.
Consequently, the release of the gas mixture
did not constitute a hazard, although the exact effect of the increased
pressure was not known.
c. Findings
(1) The licensee failed to recognize the high gas concentrations in
the WGDT's, which resulted in a failure to suspend further waste
gas additions to the "B" WGDT, and encountered considerable delay
in reducing the concentration of 02 in the WGDT's.
These failures
appear to be have been caused by several factors that included:
- Inadequate procedures to detect out of specification
readings of the WGDT parameters;
- Waiting for chemistry grab samples to verify the
existence of the high gas concentrations before taking
action to reduce these concentrations;
- Inadequate training of personnel to read and record
correct values for the gas concentrations in the
WGDT's;
- Inadequate equipment to enable plant personnel to
rapidly dilute the 02 concentration in the WGDT's (this
consisted of insufficient N on site for dilution and the
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damaged temporary N2 addition supply line to the
WGDT); and,
- The de'ay due to sampling and sample counting time
encountered when releasing WGDT-1B without first
diluting the 02 concentration with N .2
Failure to suspend further waste gas additions to a WGDT and to
reduce the concentration of 0 in a timely manner in the WGDT's is
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contrary to TS 3.7.13.5.b and is considered to be a violation.
Violation (302/86-22-01):
Failure to suspend further waste gas
additions to a WGDT and to reduce the concentration of 0 in the
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WGDT's without delay as required by TS 3.7.13.5.b.
(2) The licensee has had a history of inability to control high H2 and
0
levels in the WGDT's.
The first instance occurred during the
2time period of December 12 to 14
1984 and was identified and
reported in NRC Inspection Report 50-302/84-33.
This event, which
occurred while the plant was operating at power, resulted in the
issuance of a violation.
In a letter dated June 6, 1985, the
licensee provided a supplemental response to the violation at
which time the corrective action consisted of revising the waste
gas disposal system procedure, OP-412, and utilizing temporary N2
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addition equipment thus providing a source to add N2
to the
affected tank (s). Based upon these stated corrective actions and
the understanding by the NRC of the licensee's intent (i.e. , to
have the N addition equipment readily available when needed), the
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licensee's corrective actions were considered to be adequate.
The second instance, which occurred on January 5,1986 with the
plant in cold shutdown, was reported in NRC Inspection Report
50-302/85-44 and cited as a Deviation for failure to adhere to a
commitment.
In this event a WGDT had high 02 and H2 concen-
trations and while the tank had been isolated, the licensee was
unable to supply N2 to the tank in a timely manner because the N2
addition equipment could not be located and therefore had to be
fabricated and installed.
The licensee, in a response letter
dated March 14, 1986, denied the Deviation.
This denial stated
that the corrective actions stated in the June 6,1985 letter did
not (contrary to NRC understanding) " commit to the use of any
specific pieces of equipment, any particular location for the
equipment, nor the actual use of the equipment.."
Action statement "b" for TS 3.7.13.5 requires when the 02 and H2
concentrations in the WGDT(s) are both greater than 4% by volume
that waste gas additions be immediately suspended and that the 02
concentration be reduced to less than 4% without delay.
The
licensee has failed repeatedly to meet these requirements as
follows:
- During the time period of December 12 to 14, 1984 the
licensee failed to suspend waste gas additions from the
waste gas header and failed to reduce the 02
concentration without delay (it took approximately 102
hours to return the WGDT's to within specification);
- On January 5, 1986 the licensee was unable to
reduce the 0 concentration without delay in that it
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took approximately 42 hours4.861111e-4 days <br />0.0117 hours <br />6.944444e-5 weeks <br />1.5981e-5 months <br /> to return the "A" WGDT
to within specification; and,
- During the time period of June 17 to 19,1986 the
licensee failed to suspend waste gas additions from the
waste gas header and failed to reduce the 02
concentration without delay (it took approximately 32
hours to return the WGDT's to within specification).
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These repetitive events appear to be due to the licensee's
inability to provide adequate corrective actions.
Failure to
provide adequate corrective actions is contrary to the
requirements of 10 CFR Part 50, Appendix B, Criterion XVI and is
considered to be a violation.
Violation (302/86-22-02):
Failure to provide adequate corrective
actions to control and disposition increasing H2
and 02
concentration increases in the WGDT's.
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