ML21229A224
| ML21229A224 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 08/17/2021 |
| From: | Vincent Gaddy Region 4 Engineering Branch 1 |
| To: | Welsch J Pacific Gas & Electric Co |
| References | |
| IR 2021004 | |
| Download: ML21229A224 (9) | |
See also: IR 05000275/2021004
Text
August 17, 2021
Mr. James M. Welsch, Senior Vice President,
and Chief Nuclear Officer
Pacific Gas and Electric Company
P.O. Box 56
Mail Code 104/6
Avila Beach, CA 93424
SUBJECT:
DIABLO CANYON POWER PLANT, UNITS 1 AND 2 - NOTIFICATION OF NRC
TRIENNIAL HEAT EXCHANGER/HEAT SINK PERFORMANCE INSPECTION
(05000275/2021004 AND 05000323/2021004) AND REQUEST FOR
INFORMATION
Dear Mr. Welsch:
The purpose of this letter is to notify you that U.S. Nuclear Regulatory Commission (NRC) staff
will conduct the triennial portion of the heat exchanger/heat sink performance inspection at your
Diablo Canyon Power Plant, Units 1 and 2, from October 18-22, 2021. The onsite phase of the
inspection will consist of two reactor inspectors from the NRCs Region IV office for one week.
The inspection will be conducted in accordance with NRC Inspection Procedure (IP) 71111,
Attachment 07, Heat Exchanger/Sink Performance, dated October 21, 2020.
The objectives of the inspection are to verify that: 1) any potential heat exchanger deficiencies
which could mask degraded performance are identified, 2) any potential common-cause heat
sink performance problems that have the potential to increase risk are identified, and 3) the
licensee has adequately identified and resolved heat sink performance problems that could
result in initiating events or affect multiple heat exchangers in mitigating systems and thereby
increase risk.
To minimize the impact the inspection on the site and to ensure an efficient inspection, we have
enclosed a request for documents needed for the inspection. It is important that these requests
are fulfilled as completely and accurately as possible to minimize any additional requests during
the preparation week or during the onsite inspection. The documents have been divided into
three groups.
The first group lists information necessary for our initial inspection scoping activities.
This information should be available to the lead inspector no later than September 20,
2021. As soon as practicable, the lead inspector will communicate the initial selected
set of 2-4 risk significant or safety-related heat exchangers and/or heat sinks.
J. Welsch
2
The second group of documents requested includes those items needed to support our
in-office preparation activities. This set of documents, including calculations associated
with the selected heat exchangers and/or heat sinks, should be available no later than
October 4, 2021. This information should be separated for each inspection sample,
especially if provided electronically. Note that the inspectors may identify additional
information needed to support the inspection during this week and will communicate
those requests as soon as practicable.
The third group of documents requested includes the additional documentation identified
during in-office preparation activities as well as other resource requests necessary to
support our onsite inspection activities. The additional information or resources should
be available throughout the week of onsite inspection activities beginning on October 18,
2021.
All requested documents are to be for the time period from the onsite inspection period back to
the last triennial heat exchanger/heat sink performance inspection. If nothing addressing a
request was performed in that time period, then the request applies to the last applicable
document. If a request does not apply for any heat exchanger/heat sink sample, no response is
necessary. Include all attachments to the requests, especially corrective action program
documents.
We have discussed the schedule for this inspection with your staff and understand that our
regulatory contact for this inspection will be Ms. Amanda Sorensen of your Regulatory Affairs
organization. If there are any questions about this inspection or the documents requested,
please contact the lead inspector, Ronald Kopriva, by telephone at 817-200-1104 or by e-mail at
Ron.Kopriva@nrc.gov.
PAPERWORK REDUCTION ACT STATEMENT
This letter contains mandatory information collections that are subject to the Paperwork
Reduction Act of 1995 (44 U.S.C. 3501 et seq.). The Office of Management and Budget (OMB)
approved these information collections (approval number 3150-0011). Send comments
regarding this information collection to the Information Services Branch, Office of the Chief
Information Officer, Mail Stop: T6 A10M, U.S. Nuclear Regulatory Commission, Washington,
DC 20555-0001, or by e-mail to Infocollects.Resource@nrc.gov, and to the Desk Officer, Office
of Information and Regulatory Affairs, NEOB-10202, (3150-0011) Office of Management and
Budget, Washington, DC 20503.
PUBLIC PROTECTION NOTIFICATION
The NRC may not conduct nor sponsor, and a person is not required to respond to, a request
for information or an information collection requirement unless the requesting document
displays a currently valid OMB control number.
J. Welsch
3
In accordance with 10 CFR 2.390 of the NRCs Rules of Practice, a copy of this letter and its
enclosure will be available electronically for public inspection in the NRC Public Document
Room or from the Publicly Available Records (PARS) component of NRC's document system
(ADAMS). ADAMS is accessible from the NRC Web site at http://www.nrc.gov/reading-
rm/adams.html (the Public Electronic Reading Room).
Sincerely,
Vincent G. Gaddy, Chief
Engineering Branch 1
Division of Reactor Safety
Docket Nos. 05000275 and 05000323
License Nos. DPR-80 and DPR-82
Enclosure:
Triennial Heat Exchanger/Heat Sink
Performance Inspection Request
for Information
cc w/ encl: Distribution via LISTSERV
Vincent G. Gaddy
Digitally signed by Vincent G.
Gaddy
Date: 2021.08.17 14:35:25 -05'00'
SUNSI Review ADAMS: Non-Publicly Available Non-Sensitive Keyword:NRC-002
By: RAK Yes No Publicly Available Sensitive
OFFICE
DRS/EB1
DRS/EB1
NAME
RKopriva
VGaddy
SIGNATURE RAK
VGG
DATE
08/16/2021
8/17/2021
5
Enclosure
Request for Information
Triennial Heat Exchanger/Heat Sink Performance Inspection
Diablo Canyon Power Plant, Units 1 and 2
Inspection Report: 05000275/2021004 AND 05000323/2021004
Inspection Dates: October 18-22, 2021
Inspection Procedure: IP 71111.07, Triennial Heat Exchanger/Sink Performance
Inspector(s): Ronald Kopriva, Senior Reactor Inspector (Lead)
Chris Smith, Reactor Inspector
I.
Information Requested by September 20, 2021:
1. Heat exchanger/heat sink program documents, including NRC Generic Letter (GL) 89-13
or aging management programs
2. Responses to GL 89-13
3. Different requirements and/or commitments related to GL 89-13 or aging management
programs
4. Heat exchanger/heat sink program self-assessments
5. Updated final safety analysis report (UFSAR), technical specifications (TSs), and TS
bases
6. List of heat exchangers in order of risk significance
7. List of corrective action program documents related to heat exchangers/heat sinks
II.
Information Requested by October 4, 2021:
1. For the selected heat exchangers that are directly cooled by the service water system:
a. Performance testing (or equivalent method) documentation, including procedure
b. Periodic flow testing and/or balancing documentation, including procedure
c. Inspection (visual, eddy-current, etc.) and cleaning documentation, including
procedure
d. Tube plugging map
e. Biotic fouling and macrofouling treatment documentation, including procedure
f. Relevant design basis calculations
6
g. Applicable system health report and design basis document
h. Relevant system piping and instrumentation diagrams
i.
Heat exchanger design specification and heat exchanger data sheet
j.
Heat exchanger preventative maintenance schedule
2. For the selected heat exchangers that are directly cooled by a closed loop cooling water
system:
a. Periodic flow testing and/or balancing documentation, including procedure
b. Inspection (visual, eddy-current, etc.) and cleaning documentation, including
procedure
c. Tube plugging map
d. Evaluation of potential for water hammer
e. Chemical treatment documentation, including procedure
f. Relevant design basis calculations
g. Applicable system health report and design basis document
h. Relevant system piping and instrumentation diagrams
i.
Heat exchanger design specification and heat exchanger data sheet
j.
Heat exchanger preventive maintenance schedule
3. For the selected ultimate heat sink (UHS):
a. Forced draft cooling tower or spray pond UHS:
i. Calculations demonstrating sufficient reservoir capacity
ii. Documentation of periodic monitoring and trending of sediment, including
procedures
iii. Performance monitoring documentation of heat transfer capability,
including procedures
iv. Performance monitoring documentation of UHS structural integrity,
including procedures
b. Operation of the service water system (SWS) and UHS:
i. List of modifications to the SWS and UHS
ii. Procedures for a loss of SWS or UHS
7
iii. Biotic fouling and macrofouling treatment documentation, including
procedures
iv. Chemistry monitoring documentation, including procedures
v. Evaluation of strong-pump to weak-pump interactions
c. Performance testing of the SWS and UHS:
i. Inservice testing documentation of SWS/UHS pumps, valves, and fans,
including procedures
ii. Service water flow balance test documentation, including procedures
iii. Diagnostic testing documentation for valves that interface with safety-
related service water and nonsafety-related or nonseismic piping systems
iv. Performance testing documentation of risk-significant nonsafety-related
functions (or alignments), including procedures
d. Service water and/or closed cooling water system:
i. Inaccessible pipe testing, inspection (visual, ultrasonic, etc.), and/or
monitoring documentation, including procedure
ii. Evaluations of active thru wall pipe leaks
iii. Corrective action documents related to thru wall pipe leakage, including
trend evaluations
iv. For closed cooling water systems, trend data on make-up to the system
v. Protective coatings inspection documentation, including procedure
vi. For deep draft vertical pumps, diagnostic testing (or equivalent method)
documentation, including procedures
e. Service water intake structure (SWIS):
i. Preventive maintenance schedule for traveling screens and strainers
ii. Corrective action documents related to traveling screens, strainers, trash
racks, etc.
iii. SWS/UHS normal and abnormal operating procedures
iv. SWIS inspection documentation regarding structural integrity and silting,
including procedure
8
v. Service water pump bay water level instrument documentation related to
setpoints and calibration, including procedures
vi. SWS/UHS water temperature instrumentation documentation related to
setpoints and calibration, including procedures
vii. Evaluations of potential for frazil ice formation
viii. For underwater weir walls, evaluations of potential silt introduction
4. UHS Containment Device or Dam
a. For an above-ground UHS encapsulated by embankments, weirs or excavated
side slopes:
i. Weir or embankment design documentation
ii. Licensee or third-party dam inspection documentation used to monitor the
integrity or performance of the heat sink
iii. Calculations for sufficient reservoir capacity
iv. Significant debris or sediment build-up monitoring documentation in the
v. Corrective action program documents related to debris, debris, structural
integrity, seepage, settlement, rip rap, etc.
b. For underwater UHS weirs, structures, or excavations:
i. Underwater weirs, structures, or excavations design documentation
ii. Settlement or movement related to structural integrity and/or capacity
monitoring documentation, including procedures
iii. Sediment intrusion monitoring documentation, including procedures
iv. Calculations for sufficient capacity
v. Corrective action program documents related to settlement, movement,
structural integrity, sediment, etc.
9
III.
Additional Requests During Onsite Inspection Activities
1. Supplemental requests identified during in-office preparation activities
2. Additional requests identified during onsite inspection activities
3. Discussions with relevant subject matter experts
4. Walkdowns of selected heat exchanger/heat sink samples
5. Corrective action program documents generated as a result of this inspection
If the information requested above will not be available, please contact Ronald Kopriva as soon
as possible.
Inspector Contact Information:
Ronald Kopriva (Lead)
Senior Reactor Inspector
Reactor Inspector
817-200-1104
817-200-1095
Ron.Kopriva@nrc.gov
Chris.Smith@nrc.gov
Mailing Address:
U.S. NRC, Region IV
Attn: Ronald Kopriva
1600 East Lamar Blvd.
Arlington, TX 76011-4511