ML20062H080
| ML20062H080 | |
| Person / Time | |
|---|---|
| Site: | Yankee Rowe |
| Issue date: | 11/19/1990 |
| From: | Carrasco J, Gray E NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | |
| Shared Package | |
| ML20062H078 | List: |
| References | |
| 50-029-90-21, 50-29-90-21, IEB-79-14, NUDOCS 9012040083 | |
| Download: ML20062H080 (6) | |
See also: IR 05000029/1990021
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U.S. NUCLEAR REGULATORY COMMISSION
REGION I
Report No.
50-29/90-21
Docket No.50-029
License No.
pPR-3
Licensee
Yankee Atomic Electric Company
580 Main street
Bolton. KA. 017a0-1398
Inspection att
Rowe. Massachusetts
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Inspection conducted
5-19. 1990
//*/f * NO
Inspectort
el M
.
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J. z. carrasco, React 6r Engineer, Materials
date
and Processes Section, EB, DRS
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Approved by:
^N
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E. H. Gray, Chief / Materials and Processes
date
Section, EB, DRS-
Insoection Summarvt Report 50-029/90-21
Area Insometed: Special, announced inspection by a region-based inspector of
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licensee actions in response to NRC/IE Bulletin 79-14, Seismic Analysis of
As-built safety-Related Piping Systems; and verification of design analyses
and work performed in modifications affected by this bulletin.
Resultst-
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1.
One previously unresolved item regarding the sample population of piping
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supports to provide acceptable confidence level to assure the adequacy of
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a portion of the original IE Bulletin 79-14 inspection scope remains open.
(see section 7.0)
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2.
An unresolved item regarding an incomplete Low Precoure Safety Injection
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(LPSI) stress analysis was openod.
(see section 5.0)
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3.
One non-cited violation regarding a f ailure to document a non-conf ormance
regarding discrepancies between as installed pipe supports and the piping
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support drawings by initiating a Non-conformance Report (NCR) on a timely
basis.
(see section 6.0)
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DETAILS
1.0
Persons Contacted
Yankee Atomic Electric Company _(YAEC)
,
- N.N. St. Laurent, Plant St.perintendent
- R.M. Mitchell, Maintenance Manager
- B.
Wood, Administrative Service Manager
- D.R. Lefrancois, Senior Engineer
- J.A. Kay, Technical Service Manager
- B.W. Holmgren, Lead Mechanical Engineer
- T.
Henderson, Assisti.nt Plant Superintendent
United States Nuclear Rotulatory Commission
T. Koshy, Senior Resident Inspector
M. Markley, Resident Inspector
- denotes those who attended the exit meeting
,
2.0
Baekoround
IE Bulletin 79-14 was issued on July
2,
revised on July 18,
and
supplemented on August 15 and September 7,
1979.
The bulletin requested
licensees to take certain actions to verify that seismic analyses are
applicable to as-built plants.
To accomplish this objective, field
.erification of large bore safety class piping and pipe supports was
required.
At Yankee Nuclear power Station, the licensee contracted Cygna Energy
Services to perform the tasks required of IE Bulletin 79-14.
The only
piping in the scope of IED 79-14 which was not field verified by Cygna
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Energy Service was the Safety Injection system.
For this piping system
including pipe supports, several discrepancies were reported on dif ferent
occasions. In order to correct these discrepancies, the licensee had re-
contracted Cygna to perform a: field verification and evaluation of this
particular cystem outside the vapor containment.
Driefly, in ttrms of system description, the safety Injection syssam at
Yankee Nuclear Power Station utilizes three high pressure and three ie..'
pressure safety injection pumps to move water from the Safety Injection
Tank to the four Main Coolant System loop cold lege following a loss-of-
coolant accident .
3.0
Inspection curnose and score
The purpose of thit inspection was to assess the -adequacy of the
licensee's corrective action for identified supports that had dif ferences
between the as-built and the as-designed condition. These discrepancies
were identified on the following systems: Low Pressure Safety Injection,
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High Pressure Safety Injection, Cavity fill and spent Fuel Pit Cooling and
Pump. All these four systems made-up the Safety Injection System and are
located outside of the vapor Container in the Primary Auxiliary and. Diesel
Generator Duildings and are safety related.
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To' implement the corrective action the licensee had re-contracted Cygna to
perfer.u the following specific tasks
(a)
Walkdown and to provide as-built drawings of the piping and the
supports.
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(b)
Compare the as-built drawings against existing piping and support
drawings to identify the discrepant conditions.
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(c)
Prepare a calculation for any non-conforming configuratione to
determine if the piping and supports are within design allowabAO
conditions.
4.0
Piolna and Ploe suonort Walkdown Procedure and Imolementation
The inspector determined that the piping and support walkdowns were
performed in accordance with Reference 5.2 (Attachment D) of the Cygna's
work instruction for the field verification of non-seismic piping systems
outside the vapor container. Attachment D is the Yankee Atomic Nuclear
Service Division, Procedure No. YR-WI-02, titled " Work Instructions for
Performing Field Walkdowns of Piping and Pipe Supports Systems."
In addition to these requiremente, several additional requirements were
outlined in this cygna procedure. For examples for piping walkdowns, the
support number noted on the piping isometric or piping layout drawings was
verified; the connection type,
e.g.,
bolted flange, welded, etc., was
noted at all termination polnte.
For pipe support walkdowns, the following additional requirements were
met, for example
the general condition of the support was examined;
conditions which are deemed to be nonconforming,
e.g.
deteriorated
members, loose connections, etc., were recorded. These and several other
requirements were clearly stated in the Cygna walkdown procedure, and they
were field implemented as discussed in the next section of this report.
The inspector found the walkdown procedure to be acceptable and adequate
for this particular task and properly implemented.
5.0
Findinas
In order to assess the licensee's corrective action of piping and support
discrepancies, the inspector randomly selected pipe supports from the
Safety Injection System outelde the vapor container (VC). Inside the VC
the Shutdown Cooling System was selected to assess the licensee's original
79-14 program.
The selected supporte in the~ Safety Injection were PRSL-SH-1,
PRSH-RH-15 and PRSH-SH-1. The selected supports in the Shut-down Cooling
System were PRCH-SND-4, PRCH-SND-3, PRCH-H4 and PRCH-SND-1. The review of
these supports included the following:
Visual Inspection of the supports to determine that tho physical
configuration was reflected in the design calculation.
General location to determine that the isometric drawing reflected
the physical location of the support along the pipe run.
Spot check of the calculation, tables, interaction equations, and
ketches for accuracy, unite, and consistency.
The inspector, with the licensee's responsible engineer, examined the
system
by
a
walk-through
inspection
to
determine
the
physical
configuration of the system.
The system appeared to be in good physical condition and in the ae-design
configuration.
The inspector found the selected supports to be adequate
to perform their safety functions.
The inspector reviewed the licensee's status reporte prepared by Cygna on
the Safety Injection System outside the vapor container.
As a result of
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Cygna's review of the markups and the evaluat'.on of the HPSI System
Support, all piping in the HPSI system remains Code qualified despite the
configuration changes.
Cygna eval. ation on the Spent Fuel Pool Cooling piping and pipe supports,
indicates ihat, although there are configurational changes and support
substitutiot in the system, the piping and the supports were found to be
code-qualifaed in their as-built condition.
In the case tf LPSI Accumulator Tank Vent and Nitrogen Bottle Piping,
Cygna has com,ileted their evaluation showing that both systems are Code-
qualified in t'eir present configuration. However, the evaluation of the
discharge port.on of LPSI and the Cavity Fill Systems, is still in the
process of finat approval.
This evaluation is being done using Cygna
walkdown informa ion.
The licensee had informed the inspector that the
preliminary analysis showed that the system is within code allowable
stress values.
However, the licensee did not provide final and official
results of the analysis at the time of the exit meeting. Nevertheless, at
the exit meeting, the licensee formally committed to complete the review
of the stress analysis for the LPSI system prior October 26, 1990. Also,
corrective maintenance will be performed by the licensee on all supports
before December 31, 1990.
This is an unresolved item pending final NRC review (50-029/90-21-01).
6.0
railure to Initiato a Promet Non-conformance Report (NCR)
The inspector reviewed the findings of Cygna to deter.nine that several
discrepancies existed due to differences in the
field installed
configuration in comparison to the requirement of design as shown on the
piping drawing.
The safety significance of these discrepancies is low.
Nevertheless, these discrepancies were not properly documented via Non-
conformance Report (NCR) as required by the licensee's station procedure
(AP-0206). This is contrary to 10CFR Part 50, Appendix B, Section XV on
nonconforming materials, parts or components and section XVI on corrective
Action.
Tne licensee informed the inspector that NCRs have been initiated for
these supports.
These NCRs will be evaluated by the Plant operation
Review Committee by October 26, 1990. Maintenance requests (MRs) which
describe the corrective measures for these supports will be written and
issued by October 26, 1990.
The failure to initiate a prompt NCR constitutes a violation.
However,
the violation is not being cited because the criteria specified in
Jection V.A of the enforcement policy were satisfied.
7.0
rollow-un on Previouelv Identified Itemg
tonen) Unresolved Item 50-029/90-04-01
The-inspector reviewed'the licensee's follow-up action, in terms of the
licensee's committment to the NRC during a previous inspection.
The
committment was made to perform certain actions in order to assure the
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adequacy of the YAEC original (1979-80) inspection.
On June 1990, the licensee committed to include some systems originally
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inspected by Cygna to determine the adequacy of the implementation of
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The inspector found that the number of supports selected
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in the sample by the licensee to fulfill this commitment was not enough to
provide an acceptable level of confidence for their program under IEB 79-
14.
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In response to this finding the licensee committed to conduct a similar
verification on an expanded basis outside the containment.
The
confirmatory walkdowns will commence before the end of the year and will
be completed prior to April 1, 1991.
The size of the sample population
that will be reverified, will be at least ten percent of the total number
of supports- selected originally under IEB 79-14.
Therefore, the
unresolved item 50-029/90-04-01 will remain open, until the NRC reviews
the licensee's reverification program.
8.0
Documents reviewed
91564.004
Cigna Transmittal of Isometries and Support Drawings for
the LPSI and Cavity Fill Systems, dated July 12, 1990.
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91564.005 Rev.1
Cigna Status Report - LPSI Accumulator Tank Vent and
Nitrogen Bottle Piping, dated July 24, 1990.
91564.001
Cigna Status Report
HPSI System Supporte, dated
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July 3, 1990.
91564.007
Cygna Status Report - Spent Fuel Pool Cooling Piping and
Supports, dated July 31, 1990.
91564.006
Cygna Status Report - Safety Injection Piping Associated
with Heater E-21 and Pump P-69, dated July 31, 1990.
Yankee Atomic - Bolton Memorandum subject Nonconformance
Report (NCR)89-016 and 89-017.
AP-206,Rev.11
Station Procedure on "Nonconformance Rer;.c" - dated
July 1990.
Cygna Work Instruction for Field Verification of Non-
Seismic Piping Systems outside the Vapor Container,
dated May 10, 1990.
80023-PI-1204
Earthquake Engineering Systems (EES), Piping Isometric
SitT.2 of 3
- Safety Injection Piping, part-4.
80023-PI-1203
EES Safety Injection Piping, part 3.
SHT.5 of 5
80023-PI-1202
ESS. Safety Injection Piping, part 2.
SHT.4 of 4
Rsv. 2
80025 PI-1202
ESS Safety Injection Piping, part 2.
SHT.3
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Cygna Pipe Support Evaluation, System SI-207, Support
No. PRSH-SH-1, dated 10-11-89.
Cygna Pipe Support Evaluation, System SI-207, support
No..PRSH-RH-15, dated 10-9-89.
Cygna Pipe Support Evaluation, System SI-207, Support
No.PRSH-SH-1, dated 10-13-89.
Cygna Pipe Support Evaluation, System SC-121, Shutdown
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Cooling Piping Supporte dated t-8-88, Support No. PRCH-
SND-1 (data point 160).
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Cygna Pipe Support Evaluation, System SC-121, Shutdown
Cooling Piping, Support No. PRCH-H4 (data point 18).
Cygna pipe Support Evaluation, System SC-122, Shutdown
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Cooling Piping, Support No. PRCH-SND-3 (data point 16) .
91564 SHT.B-22
Cygna Isometric Disposition for Spent Fuel Pool.
91564 SHT.B-5
Cygna Isometric Disposition for LPSI.
91564 SHT.B-22
Cygna Isometric Disposition for HPSI.
Safety Injection System P& ids
M-7-1,2,3.
BYR-90-139
Letter from J.
K. Thayer (YAEC) to T. T. Martin (NRC)
dated October 24, 1990 regarding pipe stress and pipe
support planned activities.
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9.0
Unresolved items
Unresolved items are matters about which more information is required in
order to ascertain whether they are acceptable, violations or deviations.
Unresolved items identified during this inspection are discussed in
paragraphs 5.0 and 7.0.
10.0 Exit Meetina
The inspector met with licensee representatives (see Paragraph 1) at the
end of the inspection on October 19, 1990.
The inspector summarized the
purpose and scope of the inspection and identified the inspection
findings. At no time during this inspoction was written material provided
to the licennee by the inspectors.