IR 05000206/1981027
| ML20031A533 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 08/31/1981 |
| From: | Miller L, Zwetzig G NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | |
| Shared Package | |
| ML20031A529 | List: |
| References | |
| 50-206-81-27, NUDOCS 8109230641 | |
| Download: ML20031A533 (6) | |
Text
r
.
.
V. S. NUCLEAR REGULATORY COMMISSION OiFICE OF INSPECTION AFD ENFORCEMENT
REGION V
Report No. 50-206/81-?7 Docket No. 50-206 License No.
DPR-12 Safeguards Group Southern California Edison Company Licensee:_
P. O. Box 800
??dd Waloni Grnvp Avenne Rosemead, California 91770 Facility Name: San Onofre Unit I Inspection at: San Onofre California Inspection conducted:
July 2 - 31, 1981 Inspectors: b hM b b M 3/,/78/
L.i Mille, Ser0014 R@sident Inspector, Unit 1 J Date SiQned Date Signed Date Signed Approved by:
LL h M y/, /(f f'/
(/ Date Signed G. dwetz h Chid", Reactor ProjectsSection I, Reactor Operations Project Branch
Date Signed Summary:
Inspection on July 2 - 31, 1981 (Report No. 50-206/81-27)
Areas Inspected: Routine resident inspection of plant operations during long term outage; merithly maintenance and surveillance operations and followup on licensee event reports. The inspections involved 65 inspector _
hours by one NRC inspector.
Results:
No items of noncompliance or deviations were identified. Four items were identified which are unresolved.
8109230641 8109'1'1 RV Form 219 (2)
PDR ADOCK 05000206 G
- -
-
- -
-
-
.
-
-
.--
.-.
- -.
-
-
- -
-
- -
.
.
DETAILS 1.
Persons Contacted
- J._ G. Haynes, Manager of Nuclear Operations
- H. E. Morgan, Assistant Station Manager, Operations
- R. N. Santosuosso, Assista' t Station Manager, Maintenance n
- R. R. Brunet, Plant Sup.erintendent, Unit,I
- J. D. Dunn, Project Quality Assurance Supervisor
- B. Katz, Assistant Station Manager, Technical
- G. W. Mcdonald, Quality Assurance / Quality Control Supervisor, Unit I
- E. S. Meding,1 Health Physics; Supervisor, Unit I
- F. Briggs, Compliance Engineer
+
..,.
,
.
_
2.
Operational Safety Verificationi
_
f The inspector observed' Control Room op'erations frequently for proper
~
shift manning, for adherence' to procedures Jand limiting condi.tions for operation, and appropriate recorder and instrument indications.
The inspector discussed the statds of annunciators with Control Room operators to determine the reasons for abnonnal indications, and to determine the operators' awareness of plant status.
Shift turnovers were observed.
The Control Operator's Log was reviewed to obtain information on plant conditions, and to detennine whether regulatory requirements had been met. Other logs, including the Watch Engineer's Log and Steam Generator Chemistry Logs, were also reviewed several times.
The equipment clearance records were reviewed regularly.
Several clearance tags hung in the Control Poom were verified.
During one log review it was noted that the valve providing backup nitrogen to air-operated CV-532, a containment isolation valve, had been left shut during the recent period of power operation, apparently du9 to an oversight by the licensee. At the Exit Interview, a licer.we 1-representative stated that this valve would henceforth be included on a prestartup checklist and the Abnormal Equipment control system would be revised to more effectively monitor and control plant status.
(0150-206/81-27-03)
The inspector frequently toured the accessible arehs of the facility to assess equipment conditions, radiological controls, physical security, and personnel safety.
Radiation Controlled Area access points were generally safe and clean.
The Physical Security Plan appeared to be properly implemented. Manning of security posts, integrity of protected area barriers and isolation zones, conduct of search procedures, and personnel identification measures were all observed at intervals by the inspector.
- t
,..-
-,,m
.. _, _ -, - -,
,-.m
.
,
.-
-
-2-Plant housekeeping was adequate.
Small amounts of debris in noncritical areas wa' noticed more of ten than in the previous period, and the trend in housekeeping was down.
No immediate fire hazards were apparent, however. All fire doors were observed to be closed.
Several hydraulic shock suppressors were checked to verify proper oil level and integrity. The inspector observed that equipment needing repair was generally tagged and that a maintenance order had been initiated.
The inspector reviewed the circumstances of the reactor trips on July 2 and July 11. Both trips were related to malfunctioning instrumentation.
The July 2 trip occurred when relay AP-4B, the P-7 interlock relay, failed to block the intermediate range high startup rate trip during routine testing of the intennediate range nuclear instruments, while the reactor was at about 90 percent power.
The July 11 trip occurred when a.sniall leak in t!._ equalizing valve for the 'C' reactor coolant loop flow transmitter developed, causing a low reactor coolant flow trip signal.
The inspector stated after his review
'
of these trips that the cause of these trips, and the licensee's followup, appeared adequate.
No items of noncompliance or deviations were ' identified.
3.
Independent Inspection (Steam Generator Chemistry' Control)
The inspector noted that steam generator chemistry control continued to be weak in this period. On July 4 a saltwater leak in the condenser went undetected by the licensee during the preliminary part of the startup following the reactor trip on July 2.
As a result, chloride concentration in the steam generators reached 109 ppm and secondary pH dropped to 5.5.
The licensee elected to continue with the startup rather than to drain and refill the steam' generators; blowdowns and refilling the affected condensate hotwells were performed af ter completing the startup to bring the steam generator chemical concentrations into specification. Due to weak communications between the chemical and operations personnel, however, the concentrations were not returned within limits as rapidly as practical. On July 25, while in cold shutdown, the licensee allowed chloride concentration in the steam generators to reach 50 ppm and phosphate ion concentration to reach 6500 ppm before taking corrective action.
The licensee had sampled steam generators on July 24 and at that time a sharp increase in these parameters was evident, but no effective action was taken until the July 25 samples were obtained and analyzed.
The inspector discussed these events when they occurred and at the Exit
Interview with licensee representatives.
The inspector reiterated his concerns expressed in his June Inspection Report 80-24.
In addition, the inspector confirmed the licensee's commitment (0I 50-206/81-24-04)
to develop a meticulous and tight steam generator chemistry control program.
No items of noncompliance or deviaticns were identified.
. _ _. _, _...
.
.
-3-
,
4.
Followup on Licensee Event Report (LER)
a.
Rupture of Waste Gas Decay Tank on July 17,1981 (LER 81-018)
The inspector responded to the site when notified of this event on the evaning of July 17. At this time, approximately 11 p.m., an assessment was made with _the Region V Incident Response Center of the radiological consequences of the event.
The licensee believed that 8.8 curies of fission product gases were released by the event.
Licensee representa-tives stated at the time that no release had been observed on radioactivity monitors.
The inspector directly verified that all radiation monitoring systems indicated only background levels of radioactivity several hours after the event.
The next hy, however, the licensee infomed the inspector that the recorder point for the plant stack monitor, Area Radiation Monitoring System Channel 1214, showed some increase in radioactivity at the time of the event.
The inspector then reviewed the multipoint recorder record, which was quite faint and bardly legible.
It showed that the monitor count was faint and barely legible.
It showed that the monitor count rate had increased from a background level of 1500 cpm to 12000 cpm within' three minutes of the rupture.
This was followed by a slow decay to the background level within thirty minutes.
The detailed review of the radiation protection aspects of this event remains
,
open pending followup by NRC Region V Radiation Specialist.
The inspector closely followed the licensee's investigation of the event. The licensee determined by gas sarkples taken after the event that seven tanks contained combustible mixtures of hydrogen and oxygen:
the Volume Control -Tank, the Flash Tank, all three Radwaste Gas Decay Tanks, the Pressurizer Relief Tank, and the Reactor Coolant System Drain Tank. Based on these samples, the inspector agreed with the
licensee that the probable scenario for the event was the ignition of a combustible gas mixture being released through the cryogenic gas treatment system to the plant stack.
(The gas passing through the system is heated to several hundred degrees Fahrenheit in a portion of the system.) Apparently,:the mixture: ignited and a flame or explosion spread. rapidly back 'into the N, orth Radwaste Gas Decay Tank.
The tank's.manway failed'under the resulting pressure or shock wave stress.
'
i As described in the11icen,ee'i. Safety Analysis Report, Page 2-280,
'
and procedure, " Radioactive Waste. Gas ~ Systems," S01-5-1, oxygen.
concentration in these tanks' is'1'imited by maintaining a nitrogen atmosphere. ' Thellicensee_ determined, af ter the event that the '
source of oxygen.in the' tanks.was ' air which was present in the
~
nitrogen system.1The air entered 'the nitrogen system via connections
'
to the instrument > air. system.. 'These connections occur at air The pressuri'zer powe'r operated. relief and block valves, the' g mediu operated valve's wherecnitr6 gen provides a redundant operatin containment 7.-
_
.
< -
-
y y
.,
,,-y
-, -rg-,,--
y
,
s v~q y
y
+,,
.
,,..+*i-+y w
--
.w._
.
.
.
.
-
_-
...
b t
_4_
,
isolation valve for the nitrogen system to containment, and the auxiliary feedwater system activation valves all use nitrogen for this purpose. The nitrogen system normally operates at a pressure 10
,
to 20 psi lower than the instrument air system. Check valves are incorporated in the design to prevent intersystem leakage.
(The
,
provision of nitrogen as a backup to instrument air was part of the
TMI Action Plan modification program.)
I After the event, the licensee discovered that the check valves in j
the nitrogen system at the auxiliary feedwater system control valves, leaked badly, thereby permitting instrument air to enter the n* trogen
system in large quantities. These check valves were not tested for leakage as part of the installation procedure.
In addition, they were j
installed vertically, rather than horizontally.per the manufacturer's
reconinen ad tion.
The valves are Kerotest Manufacturing Corporation,
'Y'-type,1/2",1500 psi rating, CAM 41-series valves.
The check valves also had h'ard metal seats, rather than the soft resilient seats
.
commonly used in this service.' At the end of this inspection period,
'
the reasons for this apparent design' error were unexplained by the i,
-
(0I 50-206/81-27-04)
licensee.
This'it'em remains unresolved.
c
-
.
..
Th'e ignition source for this event was app'arently the' oxygen recombiner section of the cryogenic waste gas system.EThis system, manufactured by it.e CVI Corporation, was added by theilicensee after initial licensing
,
to provide holdupfof noble gas fission products, and thereby reduce the quantities -of radioactiv.ity released from the facility.
The system was in operation'at'the' time of ther event'.1 However, _it may be valved
out of service ;if;it'is inoperable;'if desired. The unit has'an inline oxygen analyze'r,to ' detect' oxygen ~ breakthrough' on the oxygen.recombiner.
,
The inspector deterinined that'theiman'ufacturer's Technical Manual for
the unit states ;that the unit shall^ be shutdcwn whenever the oxygen analyzer is~ out ~of s'ervice ~ r sounding an alann. However, the station o
annunciator response procedure; for'this analyzer alarm, S01-13-18,-
" Cryogenic Annunciator,"-allows continued operation of the system
,
without an operable ^ oxygen analyzer. At the end of this inspection,
):
tha reason for this discrepancy was unexplained by the licensee.
This item remains unresolved.
The inspector was informed by licensee personnel that two gas samples taken the day before the event had indicated' h.igh oxygen concentrations
in the Nitrogen System. A licensee representative stated that the
cause for these high concentrations had not been determined at the j'
time of_ tN event, some thirty hours later. Specific actions to respond'
to the-precaution stated in'the station procedures regarding high-oxygen.
l!
concentrations in waste gas system tanks did not exist in these procedures.
}
Consequently, corrective action for the condition did not occur. prior-to the event.
The inspector informed the licensee that the response
'
!-
to the high concentration samples had not been timely.
This item _ remains unresolved pending further discussion of the reasons for the delay in
!
E-taking corrective action.
'i The inspector stated at the Exit Interview that no items of-noncompliance or deviations had been identified.in connection with this event.
Three areas remain unresolved, however, as noted above.
.
s
~ Aw,
,, -
-n a
..-p'
- ,yre
,m,.
--
n-n,,.-v--w
,,,.,
mm-y,,m,,
'
.~
.-
-5-b.
Inaccurate Reactor Power Calculation (LER 81-014)
The inspector reviewed the subject Licensee Event Report and an internal memorandum which analyzed the errors which resulted from the improper installation of a feedwater flow orifice.
The inspector noted that if the licensee had relied solely on the neutron instrumentation which had been calibrated by a secondary system beat balance, the true reactor thermal power could have exceeded the 103 percent assumed in the Final Safety Analysis Report (FSAR) fcr limiting accidents. Furthermore, the inspector observed that in such a case, the power level at which the reactor tripped might have exceeded the 118 percent assumed in the FSAR, if allowances were maae for uncertainties in setpoints other than those tiue to the feedwater flow errors.
The inspector noted that the licensee had done no reanalysis of this possibility, however, because in this event, the licensee had also been monitoring electric power level and had not allowed the electric power to exceed approximately 405 Mwe (versus' 432 Mwe at full power).
The inspector, therefore, concluded that the parameters assumed as initial conditions in the FSAR had not been exceeded'in this event.
The inspector also inquired 'as\\to why the feedwater flow orifice was installed backwards. Liiensee; personnel stated that this work had not been considered to be within' the. scope of the Quality Assurance Program. That is, it was not considered to be a safety-related activity.
Licensee representatives stated that,they had instead carefully monitored all indications of reactor power during power escalation.
Then, when the anomalous indication arose,-they had identified the cause of the anomaly and corrected it. The inspector accepted this explanation, with a commitment from the senior licensee representative that station procedures would be developed promptly-to require agreement between all indications of nuclear power befo're proceeging with power escalation.
(0I50-206/81-27-01)
c.
Diesel Generator Fire on July 14, 1981 The inspector reviewed the cause of this event. As reported by the licensee, the cause of the fire was the failure of an instrument sensing lipe on the diesel lubricating oil system. Oil pumped out of the ruptured pipe ignited on the accessory end of the diesel, and a major fire occurred. After the fire, the resident inspector observed that the failed pipe did not have a counterr 't on the other Diesel Generator, which is quite similar. Licenset_ ersonnel investigated this discrepancy and determined that the pipe whicn broke was an unauthorized modification to the diesel.
No record of its installation was available, l
but there was speculation that it had been installed during the initial
'
testing of the diesel generator.
The fitting which. failed was brass, an alloy not authorized by the design specifications for tne Diesel Generators. At the Exit Interview, a licensee representative stated that, as part of the corrective action for this event, operators would
receive training to recognize unauthorized guage installations, and l
both diesel generators would be inspected promptly for such installations.
This item. remains unresolved pending receipt and review of the final LER, and the licensee's explanation of this condition.
(01 50-206/81-27-02)
- -
-.
- -
-.
.
__
_
.~
-
.
-6-r.
Monthly Maintenance and Survei'iiance Observations The inspector observed a(portion of the following maintenance and surveillance testing:
,
,
^
Pressurizer Reli,ef Valie Leak Testing (S'tation 0rder S01-I-2.3)
a.
,
b.
Area and Emergency Radiation Monitoring-hystem' Test (Station-Order A
-
-+
^
501-12.1-1)
r
^
'
,M'
,
- .
The. inspector detennined 'that these"ac'tivities did 'no't' appear to violate
.
Limiting Conditionssfor*0peration; that requirsd, administrative approval and tagouts were obtained prior :to initiating the work, and that approved procedures were bbing.used by qualified, personnel.
-
.-
.
.
1._.
-
No items of noncompliance or deviation's were identified.
-
,
6.
Unresolved Items Unresolved items are matters about wnich more information is required in-order.to ascertain whether they are acceptable itens, items of noncompliance,
'
or deviations. Four unresolved items disclosed during the inspection are discussed in Paragraph 4.
7.
Exit Interview A meeting was held on July 30,1981, (see Paragraph 1) to summarize the scope and findings of this inspection. Significant findings are discussed in the text of this report. No items of noncompliance or deviations were identified.
t
!
.
-
- - -
-
-
-
.
- - - -
. - -.
- - - - - -
-. -. - -
.
.
- - - -
.
- -
. - -...
-
. - -.
-. - - -
-.--.
J