ML20127L985
| ML20127L985 | |
| Person / Time | |
|---|---|
| Site: | Grand Gulf  |
| Issue date: | 01/29/1985 |
| From: | Crlenjak R, Panciera V NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML20127L953 | List: |
| References | |
| RTR-REGGD-01.063, RTR-REGGD-1.063 50-416-84-54, NUDOCS 8507010030 | |
| Download: ML20127L985 (5) | |
See also: IR 05000416/1984054
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UNITED STATES
NUCLEAR REGULATORY COMMISSION
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101 MARIETTA STREET,N.W.
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ATLANTA. GEORGI A 30323
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Report No.:
50-416/84-54
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Licensee: . Mississippi' Power and Light Company
Jackson, MS 39205
Docket No.:
50-416
License No. : NPF-29
Facility Name: Grand Gulf 1
Inspection Conducted:
December 6 - 17, 1984
Inspector: .H
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Approved by:
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Vindsnt~W. P;inciira, ChTef
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Reactor Projects Section 2C
Division of Reactor Projects
SUMMARY
Scope: This special inspection was conducted to evaluate the circumstances which
resulted in the licensee not meeting certain Unit 1 FSAR commitments to Regula-
tory Guide 1.63.
Results: Of the areas inspected and the review of the licensee's documentation
addressing these commitments, one apparent violation was identified; (Failure to
meet applicable regulatory requirements as specified in the license application).
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REPORT DETAILS
1.
Licensee Employees Contacted
J. E. Cross, General Manager
C. R. Hutchinson, Manager Plant Maintenance
M. J. Wright, Acting Manager Plant Operations
R. F. Rogers, General Manager Technical Assistant
L. F. Daughtery, Compliance Superintendent
J. L. Robertson, Operations Superintendent
W. A. Russel, Operations Assistant
J. D. Bailey, Compliance
V. Holmbert, Fire Project Coordinator
2.
Exit Interview / Management Meeting
On December 17, 1984, representatives of MP&L met with the NRC, at MP&L's
request, in the NRC Regional Office in Atlanta, Georgia.
The topic of
discussion was the scope of and resulting corrective actions from a recent
MP&L review that revealed a number of circuits penetrating containment that
did not meet the redundant over-current protection requirements of RG 1.63
and/or did not include circuit breakers being used for this purpose, in
Technical Specifications.
3.
Inspection Activities
This special report has been issued to address those circumstances that
resulted in a number of containment penetrating circuits of Unit I not
meeting the licensee's FSAR commitments to Regulato ry Guide (RG) 1.63.
The NRC site and regional staff reviewed and evaluated the technical
aspects
and
circumstances
surrounding
this
licensee
identified
noncompliance
and considers the corrective actions taken by MP&L to be
acceptable.
a.
Description
During July / August 1984, in the course of the licensee's updating of
Unit 2 motor control center drawings to conform to Unit 1 changes made
since suspension of engineering work on Unit 2, a discrepancy in the
design was identified. The licensee found that motor operated valve
(MOV) space heater circuits penetrating containment did not have backup
over-current protection as did the other 120 volt power panel feeds.
This condition was brought to the attention of the Bechtel Unit 1
engineers. After a review, it was determined that the commitments in
the FSAR Q&R 040.5 were not met.
MOV space heaters were not afforded
the protection of its associated FSAR Q&R category. A check was made
of 120V power feeds to containment, and it was discovered that Standby
Liquid Control System (SLCS) heat tracing also was not provided with
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backup over-current protection.
Because of these deficiencies, a review of power and control circuits
was conducted.
This review consisted of qualitative examination of all
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power and control circuits (per the circuit and raceway schedule)
penetrating the containment to determine into which category they fell,
and if there were any other circuits that did not fall into one of the
five categories. The results of that review uncovered no other defi-
ciencies.
Due to the Unit I deficiencies identified, on August 14, 1984, MP&L
requested an addition of 10 circuit breakers to the Unit 1 Technical
Specifications (TSs).
This request prompted NRR to question the
licensee's Unit 1 TS review program.
NRR requested by letter
(August 18, 1984) that MP&L address the issue. In response to the NRC
request, MP&L submitted a letter (AECM-84/0433, September 10, 1984)
discussing the identification of the FSAR commitment deficiencies
associated with the MOV space heater circuits and with the SLCS heat
tracing circuits.
The letter stated that
MP&L conducted a
"
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complete review of all circuits penetrating the primary containment to
ensure compliance with RG 1.63 and FSAR. . . ."
This submittal also
reported the licensee's corrective actions.
In late November 1984, Bechtel Unit 2 engineering personnel identified
another deficiency with regard to SLCS pump control circuits. Further
evaluation by Unit 1 personnel identified similar deficiencies with the
SLCS pump control circuit containment penetrations.
Additionally,
deficiencies were found with the containment penetrations of the
reactor protection system (RPS) scram solenoid circuits. Specifically,
the SLCS pumps had 500 VA control power transformers (CPT) which did
not conform to Category b.(5) circuits described in FSAR Q&R 040.5 and
adequate backup protection was not provided for the scram solenoid
fuses, in that the distribution breaker was underrated at 50A.
The items were not discovered during the August review since that
review only consisted of a qualitative evaluation of the circuits to
place them into one of the five FSAR Q&R categories and not a review of
the protection coordination. (For the SLCS pumps, the CPT size is not
shown on the drawing with the containment penetration and the SLCS pump
circuits were incorrectly identified as Category b.(5)).
Based on these discoveries, MP&L decided that a detailed review would
be necessary to uncover any similar situations. Therefore, Bechtel was
directed to conduct a an indepth review of the circuit protection for
each scheduled circuit penetrating the containment; ensuring that each
circuit was properly categorized and that proper breaker / fuse coordina-
tion existed.
That review was conducted from December 7-15, 1984.
The NRC was informed of these discoveries and the ongoing review on
December 7, 1984.
In addition to the findings associated with RG 1.63 commitments, the
licensee also identified 52 low voltage control circuit breakers, for
which credit was taken for penetration protection, which were not
included in Unit 1 TS.
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The results of the MP&L review were discussed with NRC Region II staff
in; a meeting held on December 17, 1984 and were documented in MP&L's
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December 18, 1984 submittal.
The following is a listing of deficien-
cies identified in the subject' review:
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'(1) SkM/IRM Drive Units
Backup protection is marginal and is not
enveloped by curves included in FSAR
(2) DC Power Supply Feed
Optical Isolator circuits contain only to
,
Isolators
a single level of penetration protection.
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(3) Horizontal Fuel
Only a single level of penetration System
Transfer Control
protection has been provided (CPT rated
Circuit
higher than
150VA)
(4) Refueling Platform
Only single level of penetration
Interlock Circuit
protection has been provided.
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(5) 'Tip Drive Control
Only a single level
of penetration
protection has been provided.
(6) Plant Communication
Only a single level of penetration
P. A. System
has been provided
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(7) Various
52 breakers not listed in Plant TSs
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b.
Safety Significance
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No deficiencies of commitments to the over-current protection provi-
sions of RG 1.63 were identified in 'the licensee's review of higher
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power conductor containment penetrations.
Circuits in the category
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have the greatest potential for penetration damage given an uninter-
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rupted over-current condition.
For instrumentation and control
circuits, however, adequate backup over-current protection was lacking
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in some instances.
Such instances were confined to circuits with
relatively small diameter conductors (maximum of #12 AWG wire) and
inherently low energy levels (low voltage controls and instrumentation
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systems).
To assess the safety significance represented by these
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noncompliances, an analysis was performed by the licensee to determine
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the impact of a proposed penetration failure on containment leakage
under postulated. loss of coolant accident (LOCA) conditions.
The
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analysis concluded that the effective fai. led penetration leakage rate
based on FSAR post - LOCA pressure profiles, when combined with
containment corrected Type A testing results, is less than the TS
allowable leakage rate limits of 0.75 La over any 24-hour period. This
analysis assumed the presence of a short circuit condition, and'a
random single failure disabling the primary over-current protection
device, coincident with a design basis LOCA.
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On the basis of this conservative treatment of a postulated penetration
failure, coincident with other design basis conditions, the licensee
concluded that the deficiencies did not represent a substantial safety
hazard.
This conclusion applies as well to those circuits whose associated
circuit breakers were not in Technical Specifications. They were all
low voltage control circuits with small diameter conductors (#12 AWG or
less).
It should be noted that while the subject breakers were not
specifically listed in TSs most of these breakers are similar in type
to those found in circuits that are currently included in the TSs. Of
course, those breakers included in the TSs were periodically tested in
accordance with the associated surveillance procedures.
The TSs
prescribe testing of representative samples for low voltage breakers to
demonstrate that breakers of a given type are operable and capable of
performing their intended function.
In addition, approximately one-third
of such circuit breakers were selected for testing, and all tested
satisfactorily. Thus, there is confidence that the subject penetrations
were adequately protected.
c.
Summary
Due to an independent, ongoing engineering design review effort on GGNS
Unit 2, discrepancies were identified by Bechtel Power Corporation in
the Unit 1 provisions for over-current protection of containment
penetrations. MP&L, upon assessing the initial findings, took immedi-
ate actions and elected to conduct an intensive review effort to
confirm that the plant's design in this area was proper and that safe
operations were not adversely impacted.
The review did identi fy
certain instances where the plant design did not comply with commit-
ments to Regulatory Guide 1.63 and circuit breakers providing over-
current protective functions were not included in the plant's TSs.
Accordingly, the statement made in the MP&L letter of September 10,
1984, that a complete review of all circuits penetrating primary
containment had been conducted is considered both false and material,
and is therefore a violation (416/84-54-01).
Plant modifications were implemented and completed prior to the Unit i
restart on December 19, 1984.
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