ML14176A813
| ML14176A813 | |
| Person / Time | |
|---|---|
| Site: | Robinson  |
| Issue date: | 12/07/1989 |
| From: | Conlon T, Merriweather N NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML14176A812 | List: |
| References | |
| 50-261-89-26, NUDOCS 8912210168 | |
| Download: ML14176A813 (11) | |
See also: IR 05000261/1989026
Text
UNITED STATES
NUCLEAR REGULATORY COMMISSION
REGION II
101 MARIETTA STREET,N.W.
ATLANTA, GEORGIA 30323
Report No.:
50-261/89-26
Licensee: Carolina Power and Light Company
P. 0. Box 1551
Raleigh, NC 27602
Docket No.:
50-261
License No.:
Facility Name: H. B. Robinson
Inspection Conducted:
October 23-27, 1989
Inspector:
.
e/
-
9
N. Merriweather
Date Singed
Approved
____
-
7
T. E.,Conion Chief
Date Signed
Plant Systems Section
Engineering Branch
Division of Reactor Safety
SUMMARY
Scope:
This routine announced inspection was conducted to review licensee's
corrective actions in response to previous inspection findings involving
environmental qualification (EQ)
of electrical equipment as discussed in NRC
Inspection Reports 50-261/87-10 and 87-19 and Notice of Violation and Proposed
Imposition of Civil Penalty issued June 16, 1988.
Results:
No specific strengths were noted in the licensee's corrective action program
for EQ problems identified in Report 50-261/87-10. The corrective actions were
considered timely but they were not always complete as evidenced by the
identification of similar problems in 1988.
The corrective action was also
limited in scope to those particular concerns identified in the report. As a,
result some significant EQ issues remained undisclosed until the EQ Program
assessment was performed in 1988. All except one of the previously identifies
violations is considered closed.
One violation remains open because the NRC
has concerns regarding the adequacy of the qualification documentation for the
conduit entrance seals installed as part of the corrective action. These seals
are submerged during a LOCA and have not been tested in a submerged condition.
For a further discussion on this problem see paragraph 2.d.
12
1D
F.UOC;IT:
2
The new items identified during this inspection are as follows:
Unresolved Item 50-261/89-26-01, the Victoreen High Range Radiation Monitor is
not installed in accordance with the qualified tested configuration.
The
configuration installed is similar to the one that failed during qualification
testing, paragraph 2.f.
Unresolved Item 50-261/89-26-02, the Licensee has not established qualification
for certain plant cables that become submerged during LOCA conditions,
paragraph 2.g.
Unresolved Item 50-261/89-26-03, the licensee has not established qualification
for a Raychem moisture seal installed on.containment penetration F01, paragraph
3.a.
Unresolved Item 50-261/89-26-04, the licensee will evaluate and determine dose
rates for Hydrogen Recombiner skid for EQ consideration, paragraph 3.b.
In the areas inspected, violations or deviations were not identified.
REPORT DETAILS
1. Persons Contacted
Licensee Employees
- W. J. Flanagan, Manager, Modifications and Configuration Control
- S. A Griggs, Technical Aide - Regulatory Compliance
- E. M. Harris, Jr., Manager - Onsite Nuclear Safety
- M. Heath, Engineering Supervisor, Modification Projects
- J. D. Kloosterman, Director, Regulatory Compliance
- R. E. Morgan, Plant General Manager
- H. J. Young, Manager QA/QC
Other licensee employees contacted during this inspection included
engineers, security force members, and administrative personnel.
Other Organizations
L. Easter, Impell Engineer
J. C. Hamlen, Impell Engineer
F. Roy, EGS-EQ Engineer
NRC Resident Inspectors
L. Garner, Senior Resident Inspector
- K. Jury, Resident Inspector
- Attended exit interview
Acronyms and initialisms used throughout this report are described in
paragraph 5.
2. Action on Previous Inspection Findings (92701, 92702)
a. (Closed) Violation 50-261/87-10-01, Cable Identification and
Qualification (One Example of Violation A in the NOV)
NRC Inspection Report 50-261/87-10 identified several deficiencies
regarding the qualification of electrical cables at Robinson. The
report states in parts,... the licensee (1) did not know which type
of cable was used for specific EQ components, (2) did not believe
that procedural control of cable installation during plant construc
tion could be relied on to identify cables, (3) had not performed
plant walkdowns or modification package reviews to address the
possible use of other cable types, and (4) had not removed any cable
2
samples for analysis. The above problem was cited as a violation in
NRC Violation and Proposed Imposition of Civil Penalty dated June 16,
1988.
The licensee responded to the violation in a letter to NRC dated
September 1, 1988 in which the licensee admits the violation and
discusses what corrective actions were taken to resolve the concerns.
The licensee indicated that they performed a review of EQ cables
located inside containment.
The cable review included both field
walkdowns, modification package reviews, a review of the conduit and
cable list drawings,
and a review of original cable specification.
Included in the review was an inspection of each cable for physical
attributes such as cable diameter, color and configurations.
This
information was compared to information available in the conduit and
cable list and the original cable specifications with unknown PVC
cable being identified.
The unknown cable was replaced with
qualified cable.
The licensee has performed an additional
Engineering Evaluation (EEG 89-080) to identify all cable that is
required to be environmentally qualified. The review resulted in a
baseline EQ cable list which provided a computerized data base of all
EQ cables.
The
EE was approved the week of the inspection on
October 26, 1989.
However, the results of the review have already
been incorporated in the EQ Master list (TMM-019)
issued June 21,
1989. Appendix B to the Master List now identifies all EQ cables by
plant ID.
The list appeared to be all inclusive based on a random
sample of components.
The only concern identified is that there was
no method to go from the EQ Master List to the associated qualifica
tion documentation without assistance from licensee EQ staff.
The
index for the EQ Data Packages and reference files was not controlled
as part of the EQ Program. The inspector informed the licensee that
the list may not be considered acceptable without information
concerning manufacturer and model numbers.
In lieu of manufacturer
and model numbers the inspector also considered it to be acceptable
to include a reference to the appropriate EQDP. The licensee chose
the later as a reasonable solution to resolving concerns regarding
auditability of EQ files and the EQ Master list. The licensee agreed
to incorporate appropriate references to the EQDPs.
It appears that the reviews performed by the licensee are adequate to
verify that all EQ cables both inside and outside containment are
supported by test data.
The licensee is now in full compliance.
This item is closed.
b.
(Closed)
Violation 50-261/87-10-02,
Crouse -
Hinds Electrical
Penetrations (Example 1 of Violation B in the NOV),
(Closed) Unresolved Item 50-261/87-19-01, EQ of Penetration Splices
The violation occurred because the electrical connectors and
shrink-fit sleeve splices used on Crouse-Hinds penetrations 'were not
3
qualified by testing or analysis. The licensee admits the violation,
but argues that enforcement action is not warranted. The issue of
whether enforcement action is warranted is still being evaluated by
NRC and will not be discussed in this report.
This report will only
address the corrective actions taken by the licensee to resolve this
concern.
The licensee has conducted a review for all components identified on
the EQ Master list located inside containment to verify that all
unqualified penetration-to-pigtail and pigtail-to-field splices have
been replaced.
Back in 1987 the licensee had made attempts to
replace all questionable splices with qualified Raychem splices prior
to startup from the outage during which this concern was raised. The
implemented special procedure (SP) 775 installed qualified splices at
the penetration -to-pigtail connection and replaced Crouse-Hinds
connectors.
The licensee replaced instrumentation cable splices
considering that the violation only related to instrumentation
circuits because the
NRC had expressed a concern about loop
accuracies.
The repairs made on the pigtail-to-field cable splices were later
found to be unacceptable because they could allow moisture intrusion
from the open end of the cable jacket to the insulated butt splices,
and consequently, the possibility for a line-to-line leakage path was
created. This problem was discussed in NRC URI 50-261/87-19-01. The
licensee confirmed this failure mode by testing. Subsequently, they
implemented modification M928 to repair the splices made under SP775.
The plant was shutdown and the repairs were completed in 1987.
In October 1988 the licensee discovered that the HVH 1-4 containment
fan cooler penetration splices were not replaced with qualified
splices. The event was reported to NRC as LER 88-024.
It was later classified by NRC as an additional example of the
original violation. The licensee discovered some other EQ components
that were omitted from the Mod 928 repair and contained the SP 775/SP
759 pigtail-to-field cable splice that could allow moisture through
the cable jacket.
A final review of splices was conducted during the 1988 refueling
outage. This review verified that all EQ circuits could be tracked
through quality documentation to a qualified configuration.
The
review also evaluated those components added to the EQ Master list
due to either a change in the environmental zone or the EQ list
re-evaluation program.
The results of the above reviews are
discussed in EE 89-044. The above items and the associated LER 88-024
are now considered closed.
4
C. (closed)
Violation 50-261/87-10-03, Limitorque Valve Operators
(Examples 2 of Violation A and Example 2 of -Violation B of the NOV
dated June 16, 1988)
Two examples of Violations were identified, failure to -provide
qualification documentation for- EQ valves (V-744A and B) and failure
to install EQ valves (V-866A and B) in accordance with the tested
configuration. The licensee responded to the violations in a letter
dated September 1, 1988. The licensee indicated that the qualifica
tion file for valves V-744A and B was updated with supplemental
information evaluating the operability of the valves during small and
large break LOCAs. The unqualified grease in the geared limit switch
housing and the internal wiring were also replaced. - Subsequently,
thevalves were replaced with Limitorque SB-3 actuators that do not
have motor brakes.
The brakes on the old actuators had not been
demonstrated to be qualified.
(See Inspection Report 87-10).
The
deficiencies identified on valves V-866A and B involved unqualified
tape splices, unqualified limit switch gear housing grease, lack of
T-drains and grease reliefs, and unidentified jumper wires.
All
these deficiencies were corrected by work request prior to startup
from the outage when they were discovered.
The licensee is now in
full compliance.
Both examples of violations are now considered
closed.
CI.
(Open) Violation 50-261/87-10-04, Cable Entrance Seals For Solenoid
Valves and Transmitters (Violation C in the NOV Dated 16 June 88)
The violation involved a failure to install conduit seals on ASCO
Solenoid valves and Rosemont 1153A transmitters.
Since the EQ
inspection the licensee installed conduit seals on all EQ equipment
identified on MOD 924-5 which included the Reactor Vessel Head Vent
Solenoid valves (RC-567 thru 572) reported on LER 88-20.
The
Regulatory Guide 1.97 items required to be EQ qualified have also
been verified by the licensee to have documentation showing that
seals have been installed.
A list of all components requiring
conduit seals is now incorporated as Appendix B to the EQ Master list
(TMM-019).
Additionally,
the Maintenance Management Procedure
MMM-025 was annotated to identify which components require conduit
seals. The seal design utilized to provide a moisture proof barrier
was provided by Patel Engineers. However, subsequent review of the
file (EQDP 21.0) and associated test reports raises several concerns
regarding the adequacy of the testing conducted on the seals and how
the test anomalies were .evaluated.
Review of both test reports
revealed that several specimens failed post LOCA pressure tests
of 100 psig of nitrogen gas.
Some failures occurred at less than
10 psig.
The failures were attributed to design problems and
technicians not following procedures.
The intent of the second test
was to verify the acceptability of the design changes and qualify
the grommets as a reusable seal.
The failures in the second test
were attributed to technician handling. The NRC concerns with both
tests are as follows:
(1) Test durations of ten and four days respectively versus 30 days
required operating time period.
(2) Questionable thermal pre-aging as a result of using an appearant
high activation energy value of 2.29 ev versus industry used
values of 1.00 ev for similar material.
(3) Test specimens were not tested submereged.
(4) Lack of use range data for cable diameters versus hole diameters
in rubber grommet.
In a letter from CP&L dated November 14, 1989, the licensee provided
additional information regarding the determination of the activation
energy and reduced time LOCA testing on Patel seals. In this letter
the licensee indicated that the activation energy for EPDM was
determined by thermogravimetric analysis (TGA) on the actual grommet
material in accordance with ASTM E698-79. The licensee believes that
this method of determining the activation energy is acceptable.
The
letter further discusses how the results of a ten day LOCA test were
extrapolated using the Arrhenius formula (assuming aging at 250 0 F
for nine days) to qualify the seals for more than the required 30
days.
All this information is currently being evaluated by NRC for
acceptability.
In addition to the above, the licensee provided a letter dated
November 17,
1989, which provides the alternative plan and schedule
for long term resolution of the environmental qualification of Patel
Conduit Seals.
This letter was submitted in accordance with a
commitment
made with NRC during a telephone conversation on
November 13, 1989. In this letter the licensee has committed to have
all actions completed prior to start-up from the 1990 refueling
outage. This item remains open.
Subsequent to the inspection the licensee reported a potential
deficiency with the wire use range of Patel conduit seals.
The
licensee identified 69 seals, including equipment in both trains of
instruments required to mitigate the consequence of a LOCA which
could be affected if equipment was flooded.
Proposed correctiv.
action includes inspection of all 69 conduit seals for proper use
range.
On those with improper use range,
the grommets will be
replaced. On ASCO solenoid valves the licensee plans on drilling a
drain hole in the conduit.
6
e.
(closed) Violation 50-261/87-10-05,
Raychem Splices (Example 3 of
Violation B in the NOV Dated 16 June 88)
A violation occurred because the licensee's EQ files at the time of
the inspection did not address the discrepancies between installed
versus tested Raychem splices.
The licensee at the time of the
inspection was conducting walkdown inspections to address the
concerns identified in IN 86-53,
"Improper Installation of Heat
Shrinkable Tubing".
The licensee completed the inspection (SP-754)
using the results of several LOCA type test reports.
The splices
found not to meet the acceptance criteria were replaced by SP 759.
In addition, the EQDP was revised to reference
the Wyle Report
(17859028) that allows a 1 inch seallength.
Based on the above,
this item is considered closed.
f. (closed) Violation 50-261/87-10-06, Instrument Accuracy (Violation D
in the NOV dated June 16, 1988)
A violation was identified during the subject inspection because CP&L
files did not adequately address instrument accuracy requirements,
particularly as it related to specified accuracies versus accuracies
obtained during the design basis accident conditions.
The licensee
responded to the violation in a letter dated September 1, 1988.
In
this letter the licensee indicated that the corrective action taken
was to begin developing loop accuracy calculations based on actual
cable.test data and to incorporate these calculations into the files.
The inspector examined five completed calculations (89-07, 89-12,89-013, 89-014 and 89-015) for EQ instruments located inside
containment.
The calculations established limits for the cabling
loss IR values to maintain assumed system accuracies.
The methods
used for calculating the loop errors considered contributions from
all components and splices in the loop.
The calculations did not
identify any components as being unqualified. Calculation No.89-014
is the loop error analysis for the worst case Victoreen (R-328) High
Range Radiation Monitors. A concern exists whether the detector and
cable assembly are installed in a qualified configuration.
This
review did not address the acceptability of the assumptions made in
this analysis.
The. qualified tested configuration used a sealed
conduit arrangement from the detector to the test chamber penetration.
However, the detectors at Robinson use Raychem Shrink tubing on the
stainless steel outer shell connector. This configuration is one of
the configurations that was tested and failed due to moisture
entering the splice area via the cable jacket. The acceptability of
the installed Victoreen detectors and assumptions made in the analysis
will be identified as Unresolved Item 50-261/89-26-01, Victoreen High
Range Radiation Monitor is not installed in accordance with the tested
configuration.
4
7
All the calculations identified above assumed the worst case IR
values for cables obtained during LOCA testing in a steam environ
ment.
Recently the licensee discovered that several EQ cables and
components become submerged. However the licensee takes the position
that the worst case IR values during LOCA testing will encompass the
IR values during submerged conditions.
The licensee indicated that
they also considered post LOCA water immersion hi-pot tests that
were conducted at ambient temperatures for 5 minutes and IPCEA
standard water immersion testing. The NRC staff does not agree with
the licensee's position that qualification for submergence can be
done by analysis and still meet the intent of NUREG 0588, paragraph
2.2(5) which requires equipment that is submerged to be demonstrated
by tests.
The testing discussed above does not fully envelope H.B.
Robinson containment accident conditions.
This item is unresolved
and will be identified as Unresolved Item 50-261/89-26-02, Cable
Submergence Qualification Data.
The above unresolved items may result in the loop error calculations
being revised at a later date.
However, the licensee's design
program will ensure that appropriate information is used in
reanalyzing the loop errors.
Not withstanding resolution of the
above unresolved items, this violation is considered closed.
g. (Closed)
Violation 50-261/87-10-07,
Taped Cable Splices (Examples
No. 4 of Violation B in the NOV dated June 16, 1988
A violation resulted because the licensee did not have adequate
documentation in the file to support a similarity analysis on how
Scotch 88 tape was chemically similar to Scotch 33 and 17 and did not
have a correlation between the tested configuration and the way the
tape was installed.
The licensee responded to the violation in a letter dated
September 1, 1988.
In this letter the licensee indicated that the
splices had been removed during the 1986 outage.
This item is
considered closed.
3. Licensee Event Reports (LERs)
a. LER 88-22, Corrected Containment Flood Level Results in Submergence
of Additional Components
Followup on the above LER revealed that the licensee has completed
all corrective actions to resolve the concern.
The licensee
performed an evaluation of the components that were submerged and
concluded that they were acceptable. However, they made repairs to
penetration FO1 to protect the Kapton insulation from interacting
with Chemical spray during a. design basis event.
The systems
associated with penetration F01 were the neutron detector NE-51,
channel I core Exit Thermocouples and the Reactor Vessel Level
8
Indication System.
Repairs made to penetration FO1 consisted of
installing a Raychem shrink seal to the stainless steel feed through
to achieve a sealed arrangement over the penetration and pigtail
cables.
The repair was implenented by (PCN 88-189/00) Mod M-977,
Rev. 0. The inspector questioned the qualification of this
configuration as a qualified seal.
The licensee provided copies of
Raychem test reports for NEIS seal kits that were tested under LOCA
conditions. However, the only configuration considered qualified by
Raychem is for use outside containment in HELB environments.
Additionally,
the seal has not been tested under submerged
conditions.
The NRC inspector did not consider the seal to be
qualified; however,
the licensee believes the EQDP is adequate to
demonstrate that this configuration is acceptable. Pending review of
the licensee's additional information this item will be tracked as
Unresolved Item 50-261/89-26-03, Review Qualification for Raychem
Penetration Seal.
As stated earlier in other parts of this report
the NRC still has questions that have not been resolved regarding
the qualification of cables and conduit seals for submergence.
b. LER 88-28, Inadequate Post Accident Containment Hydrogen Reduction/
Venting System
The licensee reported that the Hydrogen Recombiner system or Post
Accident Containment Venting system could not be operated because
several locked closed manual valves in the Reactor Auxiliary Building
Pipe Alley would be inaccessible due to high radiation levels in the
area during Post LOCA conditions. The licensee corrected the problem
by relocating the manual valves to an area that is accessible during
LOCA conditions.
The inspector was satisfied that relocating the
valves would resolve the above concern.
However, review of the EQ
master list revealed that the Hydrogen Recombiner is not considered
EQ.
This is based on the fact that the Recombiner skid will be
installed in the Fuel Handling building which will not see the direct
effects of a LOCA inside containment. However, it is considered that
the recombiner internals will see some radiation dose due to the
LOCA. It is this dose that the licensee was asked to quantify to
confirm that the recombiners need not be qualified. The licensee did
not know the dose rates anticipated, however, they contacted Duke
Power, the supplier of the Recombiner skid package, to determine what
radiation levels the Recombiner could operate in. The issue will be
tracked as Unresolved Item 50-261/89-26-04,
Dose Rate for Hydrogen
Recombiner.
4. Exit Interview
The inspection scope and results were summarized on October 27, 1989, with
those persons indicated in paragraph 1.
The inspectors described the
areas inspected and discussed in detail the inspection results listed
below.
Proprietary information is not contained in this report.
Dissenting comments were not received from the licensee. resltllite
9
Four New Unresolved Items were identified as follows:
(Open) Unresolved Item 50-261/89-26-01,
Victoreen High
Range
Radiation Monitor is not Installed in Accordance with the Tested
Configuration, paragraph 2.f
O
(Open) Unresolved Item 50-261/89-26-02, Cable Submergence Qualifica
tion Data, paragraph 2.g
o
(Open)
Unresolved Item 50-261/89-20-03,
Review Qualification for
Raychem Penetration Seal, Paragraph 3.9
(Open)
Unresolved Item 50-261/89-26-04,
Dose Rate for Hydrogen
Recombiner, paragraph 3.b
(Open) Violation 50-261/87-10-04, Remains open pending evaluation of
Patel conduit seal test data.
5. Acronyms and Initialisms
Carolina Power and Light Company
EE
Engineering Evaluation
EPDM
-Ethylene
Proplene Diene Monomers
Environmental Qualification
EQDP
Equipment Qualification Data Package
ID
Identification
IN
Information Notice
IPCEA
Insulated Power Cable Engineers Association
LER
Licensee Event Report
Loss of Coolant Accident
Modification
NESI
Nuclear Environmental Interface Kit
NRC
Nuclear Regulatory Commission
Plant Change Notice
Special Procedure
Unresolved Item
0III