ML20195J404
| ML20195J404 | |
| Person / Time | |
|---|---|
| Issue date: | 11/19/1998 |
| From: | Essig T NRC (Affiliation Not Assigned) |
| To: | Sgarro R PENNSYLVANIA POWER & LIGHT CO. |
| References | |
| PROJECT-691, RTR-REGGD-01.082, RTR-REGGD-1.082 IEB-96-003, IEB-96-3, NUDOCS 9811240274 | |
| Download: ML20195J404 (46) | |
Text
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f UNITED STATES j_
NUCLEAR REGULATORY COMMISSION 3
t WASHINGTON, D.C. 20665 4001
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November 19, 1998 Mr. Rocky Sgarro Nuclear Licensing Engineer Pennsylvania Power and Light 2 North Ninth Street Mail Code A6-1 Allentown, PA 18101
SUBJECT:
DRAFT AUDIT PLAN - BWR STRAINER PLUGGING
Dear Mr. Sgarro,
On May 6,1996, the Nuclear Regulatory Commission (NRC) issued NRC Bulletin (NRCB) 96-03, " Potential Plugging of Emergency Core Cooling Suction Strainers by Debris in Boiling-Water Reactors," requesting boiling-water reactor (BWR) licensees to implement appropriate procedural measures and plant modifications to minimize the potential for clogging of emergency core cooling system (ECCS) pool suction strainers by debris generated during a loss-of-coolant accident (LOCA). Regulatory Guide 1.82, Revision 2, (RG 1.82) " Water Sourem for Long-Term Recirculation Cooling Following a Loss-of-Coolant Accident," was issuo in May 1996 to provide non-prescriptive guidance on performing plant-specific analyses to evaluate compliance with 10 CFR 50.46. By letter dated November 20,1996, the Boiling Water Reactor Owners group (BWROG) transmitted General Electric topical report NEDO-326896, Revision 0," Utility Resolution Guidance for ECCS Suction Strainer Blockage," (URG) to the NRC staff for review. The URG provided detailed guidance to BWR utilities on methodologies for sizing new strainer designs to resolve the BWR ECCS suction strainer j
clogging issue. The staff completed its review of the URG and issued its safety evaluation report (SER) on August 20,1998. in response to NRCB 96-03, all affected BWR licensees have installed (or will install during their next refueling outage) new large-capacity passive strainers to recolve the issue. These installations have typically been conducted under 10 CFR 50.59 without detailed review by the staff. In order to achieve final closure on this issue, the staff has decided to conduct 4-6 plant audits to verify implementation prior to closing out the generic issue.
i The staff has prepared a draft audit plan which is enclosed. The plan contains detailed tables i
showing the information the staff intends to review at the site. The specific plants the staff has
/
tentatively decided to audit are listed in the opening section of the draft plan. The staff is forwarding this draft plan to the BWROG to provide the BWROG and the licensees listed on the draft audit plan the opportunity to comment on the scope of the proposed audits, the technical S
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9811240274 981119
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PDR-PROJ 691 PDR g_
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R. Sgarro November 19, 1998 content of the audit plan, and on the proposed schedule for the audits. The staff requests that any comments from the BWROG or individual licensees be forwarded to the staff in writing by December 23,1098.
Please feel free to call Mr. Rob Elli )tt at 301-415-1397 if you have any questions.
Sinperely,.
/
c--
lL,W, Thomas H. Essig, Act Chief -
Generic issues and Environmental Projects Branch Division of Reactor Program Management Office of Nuclear Reactor Regulation Project No. 691
Enclosure:
As stated cc w/enci: See next page j
R. Sgarro. November 19, 1998 e
content of the audit plan, and on the proposed schedu'le for the audits. The staff requests that any comments from the BWROG or individual licensees be forwarded to the staff in writing by December 23,1998.
2 Please feel free to call Mr. Rob Elliott at 301-415-1397 if you have any questions.
Sincerely, Original Signed By:
i Thomas H. Esnig, Acting Chief i
Generic Issues and Environmental Projects Branch
- Division of Reactor Program Management 4
Office of Nuclear Reactor Regulation' Projed No. 691 i
4 j '
Enclosure:
As stated cc w/ encl: See next page
]
DISTRIBUTION:
/ Project File-PUBLIC PGEB r/f RElliott MMarshall ASerkiz JKudrick TD'Angelo DSkay RLobel KKavanaugh CBerlinger MDavis JWilson TEssig RArchitzel CBerlinger
]
DOCUMENT NAME: g:\\MJD1%UDPLAN.LTR BC:SCSBh (A)BC:PGfB OFFICE PGEB:DRPM SC:PGEB pf, NAME MDavis:sw/40 RArchitzef CBerlinger TEssig kh DATE 11/ D /98 11//3/98 11/17/98 11/ M /98 OFFICIAL RECORD COPY
DRAFT AUDIT PLAN Implementation of NRC Bulletin 96-03 Resolutions Applicability: The staff plans to audit the following sites:
1-Duane Arnold (Mark I, GE Bol'.-on, Fibrous insulation) 2-Dresden (Mark I, PCI Bolt-on, RMI Insulation) 3-Limerick (Mark ll, ABB, Fiberglass insulation) 4-Grand Gulf (Mark lil, Enercon, Fiberglass insulation)
After performing the above audits, the staff will evaluate the need for additional audits. If additional audits are needed, the staff would mest likely select from the following plants:
Susquehanna (Mark 11, GE Bolt-on, RMI) e Fitzpatrick (Mark I, PCI Ring Girder, Fibrous Insulation)
Peach Bottom (Mark I, ABB, Fiberglass Insulation)
Perry (Mark 111, Enercon, Various Fibrous insulations)
The choice of any additional plants to be audited will be assessed by the staff based on findings from the initial four audits. If the initial audits identify any safety issues, then additional sites may be selected to determine if the issues are vendor-specific, plant-specific, or generic in nature.
Objective: To verify the implementation of NRC Buletin 96-03 (NRCB 96-03), " Potential Plugging of Emergency Core Cooling Suction Stra'ners by Debris." SpecFically, the staff w"I:
1) assess the adequacy of licensee resolutions, 2) identify if additional evaluation of licensee resolutions through the NRC inspection program is necessary, and 3) if additionalinspection effort is needed, identify areas to be inspected and guidance needed to support inspection effort (i.e., a Temporary Instruction).
Background:
On July 28,1992, an event occurred at Barseback Unit 2, a Swedish boiling water reactor (BWR), which involved the plugging of two containment vessel spray system (CVSS) suction strainers. The strainers were plugged by mineral woolinsulation that had been
)
dislodged by steam from a pilot-operated relief valve that spuriously opened while the reactor was at 435 psig. Two of the three strainers on the suction side of the CVSS pumps that were in service became partially plugged with mineral wool. Following an indication of high differential pressure across both suction strainers 70 minutes into the event, the operators shut down the CVSS pumps and backflushed the strainers. The Barsebeck event demonstrated that the potential exists for a pipe break to generate insulation debris and transport a sufficient amount of the debris to the suppression pool to clog the ECCS strainers.
Similarly, on January 16 and April 14,1993, two events involving the clogging of emergency core cooling system (ECCS) strainers occurred at the Perry Nuclear Power Plant, a domestic mm Enclosure l
i
(
DRAFT BWR. In the first Perry event, the suction strainers for the residual heat removal (RHR) pumps became clogged by debris in the suppression pool. The second Perry event involved the deposition of filter fibers on these strainers. The debris consisted of glass fibers from temporary drywell cooling unit filters that had been inadvertently dropped into the suppression pool, and corrosion products that had been filtered from the pool by the glass fibers which accumulated on the surfaces of the strainers. The Perry events demonstrated the deleterious effects on strainer pressure drop caused by the filtering of suppression pool particulates (corrosion products or " sludge") by fibrous materials adhering to the ECCS strainer surfaces.
This sludge is typically present in varying quantities in domestic BWRs, since it is generated during normal operation. The amount of sludge present in the pool depends on the frequency of pool cleaning /desludging conducted by the licensee.
7n Septenaber 11,1995, Limerick Unit 1 was being operated at 100-percent power when control rooni personnel observed alarms and other indications that one safety relief va!ve (SRV) was open. The licensee implemented emergency procedures. Attempts by the reactor operators to close the valve were unsuccessful, and a manual reactor scram was initiated.
1 drior to the opening of the SRV, the licensee had been running the "A" loop of suppression pool cooling to remove heat being released into the pool by leaking SRVs. Shortly after the manual scram, and with the SRV still open, the "B" loop of suppression pool cooling was started. The reactor operators continued their attempts to close the SRV and reduce the cooldown rate of the reactor vessel. Approximately 30 minutes later, operators observed fluctuating motor current and flow on the "A" loop of suppression pool cooling. Cavitation was believed to be the cause, and the loop was secured. After it was checked, the "A" pump was successfully restarted and no further problems were observed. After the cooldown following the blowdnwn event, the licensee sent a diver into the Unit 1 suppression pool to inspt:t the condition of the strainers and the general cleanliness of the poci. The diver found that both suction strainers in the "A" loop of suppression pool cooling were found to be almost entirely covered with a thin
" mat" of material, consisting mostly of fibers and sludge. The "B" loop suction strainers had a similar covering, but less of it. Analysis showed that the sludge primarily consisted of iron oxides and the fibers were polymeric in nature. The source of the fibers was not positively identified, but the licensee has determined that the fibers did not originate within the suppression pool, and contained no trace of either fiberglass or asbestos. This event at Limerick demonstrated the need to ensure adequate suppression pool cleanliness. In addition, it re-emphasized tnat materials other than fibrous insulation could also clog strainers.
In response to the Limerick event, the staff issued NRCB 95-02, " Unexpected Clogging of Residual Heat Rernoval (RHR) Pump Strainer While Operating in Suppression Pool Cooling Mode," on Octobe r 17,1995. The bulletin requested that licensees (1) assess the operability of their ECCS on the basis of the cleanliness of their suppression pool and ECCS strainers, (2) verify the operability of the ECCS through an appropriate pump test and strainerinspection within 120 days from the date of the bulletin, (3) establish a pool cleaning prcgram, (4) review their foreign material exclusion (FME) practices and correct any identified weaknesses, and (5) implement any additional appropriate measures for ensuring the availability of the ECCS.
Title 10, Section 50.46 of the Code of Federal Regulations (10 CFR 50.46) requires that licensees design their ECCS systems to meet five criteria, one of which is to provi:le long-term cooling capability following a successful system initiation for a sufficient duration to that the 2
um
DRAFT core temperature is maintained at an acceptably low value and decay heat is removed for the extended period of time required by the long-lived radioactivity remaining in the core. The ECCS is designed to meet this criterion, assuming the worst single failure. However, experience gained from operating events and detailed analyses has demonstrated that excessive buildup of debris from thermalinsulation, corrosion products, and other particulates on ECCS pump strainers is highly likely to occur. This creates the potential for a common-cause failure of the ECCS, which could prevent the ECCS from poviding long-term cooling following a LOCA. The staff has concluded, therefore, that licensees must take adequate steps to prevent strainer clogging in order to ensure compliance with the regulations.
As a result, NRCB 96-03 was issued on May 6,1996 requesting BWR licensees to implement appropriate procedural measures and plant modifications to minimize the potential for clogging of ECCS suppression pool suction ' strainers by debris generated during a LOCA. Regulatory Guide 1.82, Revision 2, (RG 1.82) was issued in May 1996 to provide non-prescriptive guidance on performing plant-specific analyses to evaluate compliance with 10CFR50.46. On November 20,1996, the Boiling Water Reactor Owners Group (BWROG) submitted NEDO-32686, " Utility Resolution Guidance for ECCS Suction Strainer Blockage" (also known as the URG) to the staff for review. The purpose of the URG is to give boiling-water reactor (BWR) licensees guidance for complying with the requested actions of NRCB 96-03. The staff approved the URG in an safety evaluation report (SER) dated August 20,1998. In response to NRCB 96-03, all affected BWR licensees have installed (or will install during their next refueling outage) new large-capacity passive strainers to resolve the issue. These installations have typically been conducted under 10CFR50.59 with the licensees concluding that no unreviewed safety question exists due to the installation of the new strainer designs. As a result, no detailed review of licensee resolutions for this issue has been performed by the staff.
Therefore, the staff will conduct 4-6 plant audits to verify implementation prior to closing out the generic issue for BWRs.
Audit Requirements: The following analyses and programs will be included in the audit scope:
1) the licensee's 50.59 safety evaluation, 2) the licensee's plant-specific analyses performed in response to NRCB 96-03, 3) the licensee's strainer performance and design calculations, and 4) the licensee's ongoing suppression pool cleanliness program (NRCB 95-02).
Audit Guidance 1)
Licensee's 50.59 safety evaluation
Purpose:
to perform a technical review to ensure that implementation of the strainer resolution did not create new safety concerns (e.g.,
hydodynamic loads), as well as to ensure that the licensee's safety eval tation is sufficiently comprehensive to ensure that no additional safe.y concems were caused by the strainer resolution.
Specifically, the au litor will review the licensee's 10CFR50.59 safety evaluation performed in respot se to its NRCB 96-03 resolution to assess the:
3 um
DRAFT affect of any changes to strainer hydrodynamic load calculations on plant safety e
affect of the strainer resolution on poolinventory/ accident analysis e
adequacy of scope of resolution (e.g., is change only required to low pressure e
ECCS pumps) potential for new failures not previously evaluated being created by the resolution e
potential for an increase in the probability of a failure previously evaluated e
The staff will perform a technical review of the 10CFR50.59 safety evaluation to confirm that the licensee's resolution adequately addressed the potentialimpacts of the new strainer design on plant safety.
2)
Plant specific analyses performed in response to NRCB 96-03
Purpose:
Evaluate plant-specific application of the URG in plant analyses to determine if the calculated strainer debris loadings appropriate.
Specifically, the auditor will review the licensee's plant-specific strainer analyses:
to assess the overall application of the URG to the plant e
to confirm consistent interpretation of the URG and the staff's SER e
to evaluate licensee analyses of areas where the URG did not provide detailed e
guidance (e.g., evaluation of debris generation and transport inside the bio-shield wall)
Limited confirmatory calculations will be performed, as necessary, to confirm consistency in the application of the URG methodologies.
l 3)
Strainer performance and design calculations
Purpose:
To confirm that the strainer has been adequately designed and constructed to meet its safety function.
Specifically, the auditor will review the licensee's strainer design calculations to confirm:
the adequacy of the licensee's basis for determining their strainer head loss e
the adequacy of the licensee's basis for calculation of their NPSH margin e
the adequacy of the strainer structural design and construction (e.g., ASME code e
requirements) 4)
Ongoing suppression pool cleanliness program (NRCB 95-02)
Purpose:
To confirm that the licensee's program to ensure approp iate levels of suppression pool and ECCS suction strainer cleanliness is adequate to ensure operability of the ECCS.
Specifically, the auditor will review the licensee's suppression pool cleanliness program to confirm:
4
e DRAFT the licensee has established an adequate suppression pool cleaning program e
including:
1) procedures to evaluate pool cleanliness 2) criteria for cleaning pool / strainers 3) frequency of pool evaluation and cleaning 4) basis for cleaning frequency and criteria the licensee has established adequate administrative controls on the program o
(e.g., included in the plant maintenance program)
The appendices to this audit plan provide spreadsheets detailing the specific information which will be evaluated by the auditors. The auditors will review plant drawings, calculations, strainer specification and other design documentation, as appropriate. The licensee's documentation will be used to fill in the attached spreadsheets. Confirmatory calculations will be performed by the team as shown on the spreadsheets. The completed spreadsheets will be included in the trip report for each plant.
Reporting Requirements: The results of this audit will be documented in a routine trip report.
The trip report will be addressed to the Director, Division of Systems Safety and Analysis, NRR (mail stop O-8E2). A copy of the trip report will be forwarded to the Project Manager for the audited plant. A summary report of the staff's findings on all the audits will be published following completion of the audits.
Completion Schedule: These audits should be completed by May 31,1999.
Contact:
Questions regarding this audit plan should be directed to Rob Elliott at 301-415-1397.
Statistical Data Reporting: Hours expended for this audit, including preparation time, should be reported under TAC number Originating Organization Information Organization Responsibility: This audit plan was initiated by the Containment Systems and Severe Accident Branch (SCSB).
Resource Estimate: It is estimated that each audit will require approximately 240 hours0.00278 days <br />0.0667 hours <br />3.968254e-4 weeks <br />9.132e-5 months <br /> per audit (120 hours0.00139 days <br />0.0333 hours <br />1.984127e-4 weeks <br />4.566e-5 months <br /> per auditor, with 2 NRR representatives on each audit). The staff estimates approximately 40 hours4.62963e-4 days <br />0.0111 hours <br />6.613757e-5 weeks <br />1.522e-5 months <br /> at each audit site.
Other: It is anticipated that each audit team will consist of two members of SCSB and two contractor personnel.
Training: No specific training are associated with this audit.
References NRC Bulletin 93-02, " Debris Plugging of Emergency Core cooling Suction Strainers," dated May 11,1993.
5 m
j DRAFT NRC Bulletin 93-02, Supplement 1, " Debris Plugging of Emergency Core cooling Suction Strainers," dated February 18,1994 NUREG/CR-6224, " Parametric Study of the Potential for BWR ECCS Strainer Blockage Due to LOCA Generated Debris" dated October 1995.
NRC Bulletin 95-02, " Unexpected C!ogging of Residual Heat Removal (RHR) Pump Strainer While Operating in Suppression Pool Cooling Mode," dated October 17,1995.
NRC Bulletin 96-03, " Potential Plugging of Emergency Core Cooling Suction Strainers by Debris in Boiling-Water Reactors" dated May 6,1996.
Regulatory Guide 1.82, Revision 2, " Water Sources for Long-Term Recirculation Cooling Following a Loss-of-Coolant Accident," dated May 1996.
4 GL 97-04, " Assurance of Sufficient Net Positive Suction Head for Emergency Core Cooling and i-Containment Heat Removal Pumps," dated October 7,1997.
f 6
aw>e
2 DRAFT 9
Appendix-A Plant Familiarization Note: information in blue aml gray colors is esample info or options available,
. L General Plant Data 4
s 5
Plant Name:
Containment Type:
Mark!!/Illill Vendor for Strainer:
Vendor for DH Analysis:
l Vendor for Loads Analysis:
i l
2.
Inventon of Maior Insulations Fibrous Particulate RMI Other Piping Type (TypalVol)
(TypalVol)
(TypalVol)
(Type /Vol)
Primary Piping w:n i 1200 Reactor Shielding Cavity 2 ma sse WLJ Special Structure / Component u & '.t Miscellaneous (
)
Foemme l
(Units: Volume in ft' and Fall Area in ft')
4 3.
Debris Generation Model Used in the Analysis 4
i Method #1 - All Debris in the Containment g
yes/no Method #2 yes/no i
4 Method #3 yes/no
[
Method #4 -- Not reviewed by Staff ye:Ino 1
j l
A-1 1
j
DRAFT 1
4.
Drywell Transport Factors Used in the Analysis Transport Factor is assumed equal to 1 yen /no Used URG Transport Factors y
yestno i
Plant Specific Calculations yes/no 5.
Suppression Pool Transport Factors Used in the Analysis Transport Factor is assumed equal to 1 yes/no
. Used NUREGICR-6224 Type Calculations v
yes/no Plant Specific Calculations yes/no Note: A plant may use a combination of NUREG/CR-6224 calculations for some types of debris and a TF of 1.0 for other debris.
'6.
Sources of Other Debris (Miscellaneous Debris)
Miscellaneous Debris Location Basis for Estimates Other Fibrous Paint w.;r r e usea Rust ur:6r e.te utc.
Sand / Concrete r.; r... w u s u.
Dirt and Dust u w w z a w _ 1 w ad u w ; e f:ect u ve.
Sludge ve e aumw t tea a t :;ges.
Other (
e.a. FOAM l
c nn n mrr, wevs m me reci
)
7.
Head Loss Estimation l
Vendor Correlation and Analysis Used v
yesinc Vendor LTR Enclosed yes/no Vendor LTR Previously Reviewed by Staff y
yesino Vendor tested Exact Strainers with Insulation ycsino Plant Specific Analysis (e.g., URG Correlations) yes/nc A-2 www
4 DRAFT 8.
NPSH Calculations and Comparison'with GL 97-04 Operator Throttling of ECCS Assumed y
i Time at which throttled minutes Flow and Temp after Throttling used in Cales.
GPM/oF Maximum Pool Temperature v
Assumed Containment Overpressure psi Staff reviewed the NPSH Calculation Reference No:
Date of Approval:
l 9.
Suppression Pool Cleanliness Program (SPCP) f SPCP Part of Maintenance Rule (10 CFR 50.65) Program y
yes/no SPCP Addressed NRCB 95-02 y
yes/no 10.
Codes and Standards (Comnarison with Licensing Basis /UFSAR)
~
~
Quality Assurance Requirements v
yas/no 10 CFR Appendix-B y
yes/no ASME Certificate Required v
yes/no Materials Conform to ASTM Specifications v
Certified Material Test Reports are Provided v
5 Design / Fabrication Qualified ASME Section Ill, Subsection NC v
Qualified ASME Section Ill, Class 2 v
3 Other(
)
Welding Qualified to ASME Section IX v
Other (
)
NDE per ASME Section lli Critical welds examined by liquid penetrant v
All Other Welds Visually Examined v
i Other (
)
/
1 A-3 www
DRAFT Appendix-B Head Loss Estimate Calculations Note: It is assumed that these tables will he filled in by the stalf. Licensee should ensure that such information is available in the licensee calculation and reports.
1.
Destruction Pressures Used insulation Type Plant Staff Transco RMI Cal-Sil with Al Jacket K-Wool Temp-Matwith ss wire retainer Knaupf Jacketed Nukon Unjacketed Nukon Koolphen-K MIRROR from Diamond Min-K Other:
(
)
(
)
(
)
(
)
l B-1 mem
DRAFT i-2.
' Area of the Zone ofInfluence Used (or Eauivalent L/D for Sohere )
insulation Type Break #1 Break #2 Break #3 Break #4 Plant Staff Plant Staff Plant Staff Plant Staff I
Transco RMI Cal-Sil with Al Jacket K Wool Temp-Mat Knaupf Jacketed Nukon Unjacketed Nukon Koolphen-K il MIRROR RMI Min-K Other:
(
)
(
)
(
)
l,
(
)
3 Volume of Debris Generated by the Break l
Insulation Type Break #1 Break #2 Break #3 Break #4 4
Plant Staff Plant Staff Plant Staff Plant Staff Transco RMI Cal-Sil with Al Jacket K-Wool Temp-Mat f
Knaupf Jacketed Nukon l
Unjacketed Nukon Koolphen-K MIRROR RMI j-Min-K 1
Other:
l
(
)
I
(
)
(
)
(
)
l If Breaks < 2. then Vendor Data Supports screening out rest of breaks v or X Plant analyses showed MLOCA's are not important v or X 1
B-2 I
].
DRAFT 4.
Drvwell Debris Transport Fractions Used in the Analysis t
insulation Type Break #1 Break #2 Break #3 Break #4 Plant Staff Plant Staff Plant Staff Plant Staff Transco RMI Cal-Sil with Al Jacket K-Wool Temp-Mat i
Knaupf Jacketed Nukon Unjacketed Nukon Koolphen-K MIRROR RMI Min-K Other:
(
)
(
)
(
)
(
)
5 Wetwell Debris Transport Fractions Used in the Analysis i
insulation Type Break #1 Break #2 Break #3 Break #4 Plant Staff Plant Staff Plant Staff Plant Staff Transco RMI Cal-Sil with Al Jacket K-Wool I
Temp-Mat Knaupf Jacketed Nukon Unjacketed Nukon i
Koolphen-K MIRROR RMI Min-K Other.
(
)
(
)
(
)
(
)
I I
f B-3 somm
~
DRAFT 5.
Net Insulation Debris on the Strainer Insulation Type Break #1 Break #2 Break #3 Break #4 Plant Staff Plant Staff Plant Staff Plant Staff Transco RMI Cal-Sil with Al Jacket K-Wool Temp-Mat Knaupf Jacketed Nukon Unjacketed Nukon Koolphen-K MIRROR RMI Min-K Other:
(
)
(
)
(
)
(
)
6.
Miscellaneous Debris Plant Est.
URG Recom Staff Estimate Debris Type Gen T. F.
Gen T.F.
Gen T.F.
Other Fibrous Paint Rust Sand / Concrete Dirt and Dust Sludge Other ( FOAM
)
Other (
)
l B-4
\\
DRAFT l..
j 7.
ECCS Flow Rate and Design Details l
lRHR #1lRHR #2lRHR #3lRHR #4l CS #1 [ CS #2 l
Before Throttling Flow Rate (GPM)
Pool Temperature (oF) i Wetwell Pressure (psia)
NPSH Margin After Throttling (Time:
min) l Flow Rate (GPM) l Pool Temperature (oF)
Wetwell Pressure (psia) l NPSH Margin i
t j
8.
Strainer Flow Rates and Design Details l
l Str #1l Str #2 l Str #3 l Str #4 l Str #5 l Str #6 l
Previous Strainer i
Flow Rate Data Full Design i
Full Single Failure Throttle Single Failure Throttle Design Outer Diameter Active Length Flange Diameter Plate Area Clean Head Loss Replacement Strainer Flow Rate Data I
Full Design Full Single Failure Throttle Single Failure Throttle Design Outer Diameter Active Length Plate Area (Effective)
Gap Volume Circumscribed Area Clean Head Loss Basis for Clean DH B-5 wam
I DRAFT l
9.
Strainer Head Loss Calculations l
i Unthrottled Flow (sinele failure or desien case): For common header plants design flow may result in worse head loss.
i l
Property Straher #1 Strainer #2 Strainer #3 Strainer #4 Strainer #5 Strainer #6 Plant Staff Plant Staff Plant Staff Plant Staff Plant Staff Plant Staff l
Circumscnbed Velocity i
i i
i i
i i
Plate Velocity i
i i
i i
i i
l Temperature E
i i
l I
Mass of Fibrous Debris i
i i
i i
i j
i Volume of Fibrous Debris!
i i
i i
t i
i i
i j
l
% Occupancy of Gap i
i i
i i
i i
i i
i Area of Reflective Metallici i
i i
i i
K, i
i y
l Kn i
i.
i Mass of Corrosion Prod.
5 Correlation Head Loss s
i i
i i
i i
{
Bump-up Factors i
i i
y i
i j
i l
Paint Chips i
i j
j l
Rust i
i i
s g
i i
l Sand i
i i
i i
i i
[
Dirt / Dust i
i i
i i
i i
l Zinc h
i i
Calcium-Silicate i
i i
i Net Debns Head Loss i
E i
i i
Clean Head Loss i
i i
i i
i i
i i
Total Head Loss i
i e
i i
i i
i i
i i
j NPSH Margin Left i
l i
j l
l l
j j
[
I r
h t
w B-6
[
==
l i
DRAFT Throttled Flow:
Property Strainer #1 Strainer #2 Strainer #3 Strainer #4 Strainer #5 Strainer #6 Plant Staff Plant Staff Plant Staff Plant Staff Plant Staff Plant Staff l
Circumscnbed Velocity i i
i i
i Plate Velocity 5
i i
i i
i Temperature i
i i
i g
f Mass of Fibrous Debris i i
i i
i i
i i
Volume of Fibrous Debrisi i
i
% Occupancy of Gap y
i l
Area of Reflective Metallici i
i y
}
l Ke i
i
=
l K%
~
i g
Mass of Corrosion Prod.
i i
i i
Correlation Head Loss i
i w
i i
y i
l Bump-up Factors i
i i
i i
i Paint Chips i
i i
i i
i l
Rust i
i i
i i
j Sand i
i i
i i
i i
i Dirt / Dust i
i i
i i
i t
Zinc i
i i
i i
i Calcium-Silicate i
i i
s i
i i
i t
Net Debris Head Loss i
i i
i i
s I
Clean Head Loss i
I Total Head Loss i
i E
i i
i NPSH Margin Left i.
i i.
i i
5 i
B-7 l
l
_. _ _ _ -.__ _.. _. _ _. _ __ _ _ ___. _ _ __. ~... _ _.
l DRAFT 1
10.
Overall Strainer Performance Str #1 Str #2 Str #3 Str #4 ' Str Eb l Str #6 Strainer Plate Area increase Circumscribed Area increas Volume Increase Hole Dimension Change Volume of Gap DH Old (RG 1.82, Rev. O or 1)
DH New (RG 1.82, Rev. 2)
Cont. Over Pres. Requirement B-8
O DRAFT t
Appendix-C Codes / Standards and Suppression Pool Cleanliness Program 1.
Does the Strainer Design, Material Procurement and Manufacturing meat Codes and Standards in the following Deciplines Quality Assurance Reauirements 10 CFR Appendix-B ASME Certificate Required Materials Conform to ASTM Specifications Certified Material Test Reports are Provided Deslan/ Fabrication Qualified ASME Section lil, Subsection NC Qualified ASME Section Ill, Class 2 Other (
)
Welding Qualified to ASME Section IX Other (
)
NDE ner ASME Section lli Critical welds examined by liquid penetrant All Other Welds Visually Examined Other (
)
2.
Has the licensee incorporated its suppression pool cleanliness program into the scope of its maintenance rule (10CFR50.65) program?
If the answer to number 1 above is yes, then O
What goals have been established by the licensee for suppression pool cleanliness? Strainer cleanliness?
O How is the licensee monitoring its suppression pool / strainer cleanliness goals?
O If monitoring is not required, what preventative maintenance is the licensee performing to ensure that the suppression pool and associated strainers can perform their intended safety function?
O What is the frequency of monitoring or preventatlve maintenance (as applicable to the licensee's program)?
C-1
,4*
e-DRAFT c
O When was the last ai,sessment of suppression pool performance / goals or 4:
preventative maintenance performed, and what were the licensee's findings?
O What related industry experience was considered in the last assessment and what were the licensee's conclusions relative to applicability of this experience to their plant?
O What adjustments, if any, were made to the licensee's programs based on the last assessment?
O Has the licensee considered the affect of its maintenance or monitoring activities on total availability of safety systems?
O Has the licensee taken steps to minimize unavailability of safety systems due to
[
suppression pool / strainer monitoring or maintenance activities?
O When is the next assessment of performance / goals or preventative maintenance scheduled?
l 1
If the answer to number 1 above is no, what is the licensee's basis for not including the suppression pool and/or suction strainers in the scope of its maintenance rule activities?
L-in addition, did the licensee establish a suppression pool cleanliness program as requested in NRC Bulletin 95-02?
i i
O How is the licensee ensuring the operability of the ECCS relative to ensuring an adequately clean suppression pool and ECCS suction strainers?
O How is the licensee administratively controlling its suppression pool / strainer
]
cleanliness program?-
O What criteria has the licensee established for suppression pool and strainer l
cleanliness?
O What is the licensee's planned frequency for cleaning the suppression pool and strainers?
d 4
4 I
]
3 l
C-2 unem
b 8
Project No. 691 Boiling Water Reactor Owners Group cc:
Thomas J. Rausch, Chairman W. Glenn Warren Boiling Water Reactor Owners' Group Southern Nuclear / Georgia Power Commonwealth Edison Company E.1. Hatch Nuclear Plant Nuclear Fuel Services PO Box 1295 M/C B052 1400 Opus Place,4th Floor ETWill Birmingham, AL 35201 Downers Grove, IL 60515 Carl D. Terry Dennis B. Townsend Vice President, Nuclear Engineering GE Nuclear Energy Niagara Mohawk Power Corporation M/C 182 Nine Mile Point-2 175 Cuitner Avenue i
PO Box 63 San Jose, CA 95125 Lycoming, NY 13093 Drew B. Fetters Thomas A. Green PECO Energy GE Nuclear Energy Nuclear Group Headquarters Mail Code 182 MC 62C-3 175 Curtner Avenue 965 Chesterbrook Blvd.
San Jose, CA 95125 Wayne, PA 19087 John Hosmer Commonwealth Edison Executive Towers,4th Floor 1400 Opus Place Downers Grove,IL 60515 1
George T. Jones Pennsylvania Power & Light MC A6-1 Two North Ninth Street Allentown, PA 18101 Lewis H. Sumner Southern Nuclear / Georgia Power E.1. Hatch Nuclear Power Plant 40 Inverness Parkway PO Box 1295 Birmingham,GA 35201 John Kelly New York Power Authority 14th Floor Mail Stop 14K Centroplex Building 123 Main Street White Plains, NY 10601
PD$
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UNITED STATES NUCLEAR REGULATORY COMMISSION f
g WASHINGTON, D.C. 20555-0001 November 19. 1998 Mr. Rocky Sgarro Nuclear Licensing Engineer Pennsylvania Power and Light 2 Ncrth Ninth Street Mail Code A6-1 Allentown, PA 18101
SUBJECT:
DRAFT AUDIT PLAN - BWR STRAINER PLUGGING
Dear Mr. Sgarro,
On May 6,1996, the Nuclear Regulatory Commission (NRC) issued NRC Bulletin (NRCB) 96-03. " Potential Plugging of Emergency Core Cooling Suction Strainers by Debris in Boiling-Water Reactors," requesting boiling-water reactor (BWR) licensees to implement appropriate procedural measures and plant modifications to minimize the potential for clogging of emergency core cooling system (ECCS) pool suction strainers by debris generated during a loss-of-coolant accident (LOCA). Regulatory Guide 1.82, Revision 2, (RG 1.82) " Water Sources for Long-Term Recirculation Cooling Following a Loss-of-Coolant Accident," was issued in May 1996 to provide non-prescriptive guidance on performing plant-specific analyses to evaluate compliance with 10 CFR 50.46. By letter dated November 20,1996, the Boiling Water Reactor Caners group (BWROG) transmitted General Electric topical report NEDO-326896, Revision 0," Utility Resolution Guidance for ECCS Suction Strainer Blockage," (URG) to the NRC staff for review. The URG provided detailed guidance to BWR utilities on methodologies for sizing new strainer designs to resolve the BWR ECCS suction strainer clogging issue. The staff completed its review of the URG and issued its safety evaluation report (SER) on August 20,1998. In response to NRCB 96-03, all affected BWR licensees have installed (or will install during their next refueling outage) new large-capacity passive strainers to resolve the issue. These installations have typically been conducted under 10 CFR 50.59 witn' out detailed review by the staff. In order to achieve final closure on this issue, the staff has decided to conduct 4-6 plant audits to verify implementation prior to closing out the generic issue.
The staff has prepared a draft aud;t plan which is enclosed. The plan contains detailed tables showing the information the staff intends to review at the site. The specific plants the staff has tentatively decided to audit are listod in the opening section of the draft plan. The staff is forwarding this draft plan to the BWROG to provide the BWROG ano the licensees listed on the draft audit plan the opportunity to comment on the scope of the proposed audits, the technical
2 R. Sgarro November 19, 1998 i
i content of the audit plan, and on the proposed schedule for the audits. The staff requests that l
any com.ments from the BWROG or individual licensees be forwarded to the staff in writing by
. December 23,1998.
Please feel free to call Mr. Rob Elli itt at 301-415-1397 if you have any questions.
3 Sint.erely, 1
[(m, 3
Thomas H. Essig, Act Chief Generic issues and Environmental Projects Branch Division of Reactor Program Management Office of Nuclear Reactor Regulation 3roject No. 691 t.
'losure: As stated cc w/ encl: See next page j
l s
f f
4 l'
A 2
-,-~
s I
R. Sgarro
-2 November 19, 1998
- content of the audit plan, and on the proposed schedule for the audits. The staff requests that any comments from the BWROG or individual licensees be forwarded to the staff in writing by December 23,1998.
Please feel free to call Mr. Rob Elliott at 301-415-1397 if you have any questions.
I r
Sincerely, Original Signed By:
Thomas H. Essig, Acting Chief Generic issues and Environmental Projects Branch Division of Reactor Program Management
' Office of Nuclear Reactor Regulation ~
J Project No. 691 l
Enclosure:
As stated i
cc w/ encl: See next page DISTRIBUTION:
Project File /PUBLIC PGEB r/f RElliott MMarshall ASerkiz JKudrick TD'Angelo DSkay RLobel KKavanaugh CBerlinger MDavis JWilson TEssig RArchitzel CBerlinger DOCUMENT NAME: g:\\MJD1%UDPLAN.LTR
+
OFFICE PGEB:DRPM SC:PGEB pf, BC:SCSB ( /-
(A)BC:PGEB NAME MDavis:sw 4k!h RArchitzed CBerlinger TEssig h DATE 11/ i'l/98 11//3/98 11/
/98 11/ pg /98 OFFICIAL RECORD COPY -
- -.c.
\\
DRAFT AUDIT PLAN Implementation of NRC Bulletin 96-03 Resolutions Applicability: The staff plans to audit the following sites:
1--
Duane Arnold (Mark I, GE Bol?on, Fibrous insulation) 2 Dresoen (Mark 1, PCI Bolt-on, RMI Insulation) 3-Limerick (Mark 11, ABB, Fiberglass insulation) 1 4-Grand Gulf (Mark til; Enercon, Fiberglass insulation)
After performing the above audits, the staff will evaluate the need for additional audits. If additional audits are needed, the staff would most likely select from the following plants:
)
e.
Susquehanna (Mark II, GE Bolt-on, RMI) i Fitzpatrick (Mark I, PCI Ring Girder, Fibrous Insulation) e Peach Bottom (Mark I, ABB, Fiberglass insulation) e Perry (Mark 111, Enercon, Various Fibrous insulations) e
-The choice of any additional plants to be audited will be assessed by the staff based on findings
'from the initial four audits. If the initial audits identify any safety issues, then additional sites 4
may be selected to determine if the issues are vendor-specific, plant-specific, or generic in nature.
Objective To verify the implementation of NRC Bulletin 96-03 (NRCB 96-03), " Potential Plugging of Emergency Core Cooling Suction Strainers by Debris." Specifically, the staff will-1) assess the adequacy of licensee resolutions, 2) identify if additional evaluation of licensee resolutions through the NRC inspection program is necessary, and 3) if additional inspection effort is needed, identify areas to be inspected and guidance needed to support inspection effort (i.e., a Temporary Instruction).-
Background:
On July 28,1992,. an event occurred at Barsebeck Unit 2, a Swedish boiling water reactor (BWR), which involved the plugging of two containment vessel spray system (CVSS) suction strair ers.- The strainers were plugged by mineral wool insulation that had been dislodged by steam from a pilot-operated relief valve that spuriously opened while the reactor i was at 435 psig. Two of the three strainers on the suction side of the CVSS pumps that were in service became partially plugged with mineral wool. Following an indication of high differential
. pressure across both suction strainers 70 minutes into the event, the operators shut down the CVSS pumps and backfiushed the strainers. The Barsebeek event demonstrated that the potential exists for a pipe break to ger4 rate insulation debris and transport a sufficient amount of the debris to the suppression pool to clog tise ECCS strainers.
Similarly, on January 16 and April 14,1993, two events involving the clogging of emergency core cooling system (ECCS) strainers occurred at the Perry Nuclear Power Plant, a domestic 1M!99
)
Enclosure l
4 DRAFT d
i 1
BWR. In the first Perry event, the suction strainers for the residual heat removal (RHR) pumps became clogged by debris in the suppression pool. The second Perry event involved the deposition of filter fibers on these strainers. The debris consisted of glass fibers from j
temporary drywell cooling unit filters that had been inadvertently dropped into the suppression 2
pool, and corrosion products that had been filtered from the pool by the glass fibers which i
j accumulated on the surfaces of the strainers. The Perry events demonstrated the deleterious effects on strainer pressure drop caused by the filtering of suppression pool particulates (corrosion products or " sludge") by fibrous materials adhering to the ECCS strainer surfaces.
]
This sludge is typically present in vary.ng quantities in domestic BWRs, since it is generated
]
during normal operation. The amount of sludge present in the pool depends on the frequency j
of pool cleaning /destudging conducted by the licensee.
1 On September 11,1995, Limerick Unit 1 was being operated at 100-percent power when control room personnel observed alarms and other indications that one safety relief va!ve (SRV) i was open. The licensee implemented emergency procedures. Attempts by the eactor operators to close the valve were unsuccessful, and a manual reactor scram wt.s initiated.
Prior to the opening of the SRV, the licensee had been running the "A" loop of suppression pool cooling to remove heat being released into the pool by leaking SRVs. Shortly after the manual scram, and with the SRV still open, the "B" loop of suppression pool cooling was started. The reactor operators continued their attempts to close the SRV and reduce the cooldown rate of the reactor vessel. Approximately 30 minutes later, operators observed fluctuating motor current and flow on the "A" loop of suppression pool cooling. Cavitation was believed to be the cause, and the loop was secured. After it was chWed, the "A" pump was successfully j
restarted and no further problems were observed. ider the cooldown following the blowdown event, the licensee sent a diver into the Unit 1 suppression pool to inspect the condition of the strainers and the general cleanliness of the pool. The diver found that both suction strainers in j
the "A" loop of suppression pool cooling were found to be almost entirely covered with a thin
" mat" of material, consisting mostly of fibers and sludge. The "B" loop suction strainers had a similar covering, but less of it. Analysis showed that the sludge primarily consisted of iron t
oxides and the fibers were polymeric in nature. The source of the fibers was not positively
)
identified, but the licensee has determined that the fibers did not originate within the j
suppression pool, and contained no trace of either fiberglass or asbestos. This event at i
Limerick demonstrated the need to ensure adequate suppression pool cleanliness. In addition, it re-emphasized that materials other than fibrous insulation could also clog strainers.
In response to the Limerick event, the staff issued NRCB 95-02, " Unexpected Clogging of Residual Heat Removal (RHR) Pump Strainer While Operating in Suppression Pool Cooling i
l Mode," on October 17,1995. The bulletin requested that licensees (1) assess the operability of their ECCS on the basis of the cleanliness of their suppression pool and ECCS strainers (2) verify the operability of the ECCS through an appropriate pump test and strainer inspection j
within 120 days from the date of the bulletin, (3) establ,sh a pool cleaning program, (4) review j
their foreign material exclusion (FME) practices and correct any identified weaknesses, and (5) implement any additional appropriate measures for ensuring the availability of the ECCS.
j Title 10 Section 50.46 of the Code of Federal Regulations (10 CFR 50.46) requires that licensees design their ECCS systems to meet five criteria, one of which is to provide long-term cooling capability following a successful system initiation for a sufficient duration so that the 4
I 2
w.
2 DRAFT core temperature is maintained at an acceptably low value and decay heat is removed for the extended period of time required by the long-lived radioactivity remaining in the core. The ECCS is designed to meet this criterion, assuming the worst single failure. However, experience gained from operating events and detailed analyses has demonstrated that excessive buildup of debris from thermalinsulation, corrosion products, and other particulates j
on ECCS pump strainers is highly likely to occur. This creates the potential for a common-cause failure of the ECCS, which could prevent the ECCS from providing long-term cooling following a LOCA. The staff has concluded, therefore, that licensees must take adequate steps to present strainer clogging in order to ensure compliance with the regulations.
As a result, NRCB 96-03 was issued on May 6,1996 requesting BWR licensees to implement appropriate procedural measures and plant modifications to minimize the potential for clogging of ECCS suppression pool suction strainers by debris generated during a LOCA. Regulatory Guide 1.82, Revision 2, (RG 1.82) was issued in May 1996 to provide non-prescriptive j
guidance on performing plant-specific analyses to evaluate compliance with 10CFR50.46. On November 20,1996, the Boiling Water Reactor Owners Group (BWROG) submitted NEDO-32686, " Utility Resolution Guidance for ECCS Suction Strainer Blockage"(also Known as the URG) to the staff for review. The purpose of the URG is to give boiling-water reactor (BWR) licensees guidance for complying with the requested actions of NRCB 96-03. The staff approved the URG in an safety evaluation report (SER) dated August 20,1998. In response to NRCB 96-03, all affected BWR licensees have installed (or will install during their next refueling outage) new large-capacity passive strainers to resolve the issue. These installations have typically been conducted under 10CFR50.59 with the licensees concluding that no unreviewed safety question exists due to the ins;allation of the new strainer designs. As a result, no detailed review of licensee resolutions for this issue has been performed by the staff.
Therefore, the staff will conduct 4-6 plant audits to verify implementation prior to closing out the generic issue for BWRs.
Audit Requirements: The following analyses and programs will be included in the audit scope:
1) the licensee's 5n 59 safety evaluation, 2) the licensee's p ent-specific analyses performed in response to NRCB 96-03, 3) the licensee's strainer performance and design calculations, and 4) the licensee's ongoing suppression pool cleanliness program (NRCB 95-02).
Audit Guidance 1)
Licensee's 50.59 safety evaluation
Purpose:
to perform a technical review to ensure that implementation of the strainer resolution did not create new safety concerns (e.g.,
hydrodynamic loads), as well as to ensure that the licensee's safety evaluation is sufficiently comprehensive to ensure that no additional safety concerns were caused by the strainer resolution.
Specifically, the auditor will review the licensee's 10CFR50.59 safety evaluation performed in response to its NRCB 96-03 resolution to assess the:
3 0.w
i DRAFT affect of any changes to strainer hydrodynamic load calculations on plant safety e
[
affect of the strainer resolution on poolinventory/ accident analysis e
1 adequacy of scope of resolution (e.g., is change only required to low pressure e
ECCS pumps) potential for new failures not previously evaluated being created by the resolution e
j.
potential for an increase in the probability of a failure previously evaluated e
The staff will perform a technical review of the 10CFR50.59 safety evaluation to confirm that the licensee's resolution adequately addressed the potentialimpacts of the new
[
strainer design on plant safety.
2)
Plant specific analyses performed in response to NRCB 96-03
Purpose:
Evaluate plant-specific application of the URG in plant analyses to
}
determine if the ca!culated strainer debris loadings appropriate.
j.
SpecificaiP/ the auditor will review the licensee's plant-specific strainer analyses:
4
)
to assiss the overall application of the URG to the plant e
e to conf rm consisterit interpretation of the URG and the staff's SER
.to eva'uate licensee analyse.s of areas w 1ere the URG did not provide detailed e
guidance (e.g., evaluation of debris gent ration and transport inside the bio-shield wall)
Limited confirmatory calculations will be performed, as necessary, to confirm consistency in the application of the URG methodologies.
3)
Strainer performance and design calculations
Purpose:
To confirm that the strainer has been adequately decigned and constructed to meet its safety function.
Specifically, the auditor will review the licensee's strainer design calculations to confirm:
the adequacy of the licensee's basis for detennining their strainer head loss e
the adequacy of the licensee's basis for calculation of their NPSH margin e
the adequacy of th; strainer structural design and construction (e.g., ASME code e
requirements) 4)
Ongoing suppression pool cleanliness program (NRCB 95-02)
Purpose:
To confirm that the licensee's program to ensure appropriate levels of suppression pool and ECCS suction strainer cleanliness is adequate to ensure operability of the ECCS.
Specifically, the auditor wiil review the licensee's suppression pool cleanliness program to confirm:
4 mem
DRAFT the licensee has established an adequate suppression pool cleaning program i
e including:
1) procedures to evaluate pool cleanliness 2) criteria for cleaning pool / strainers 3) frequency of pool evaluation and cleaning 4) basis for cleaning frequency and criteria the licensee has established adequate administrative controls on the program e
(e.g., included in the plant maintenance program)
The appendices to this audit plan provide spreadsheets detailing the specific information which will be evaluated by the auditors. The auditors will review plant drawings, calculations, strainer specification and other design docunientation, as appropriate. The licensee's documentation will be used to fillin the attached spreadsheets. Confirmatory calculations will be performed by the team as shown on the spreadsheets. The completed spreadsheets will be included in the trip report for each plant.
Reporting Requirements: The results of this audit will be documented in a routine trip report.
The trip report will be addressed to the Director, Division of Systems Safety and Analysis, NRR (mail stop O-8E2). A copy of the trip report will be forwarded to the Project Manager for the audited plant. A summary report of the staff's findings on all the audits will be published following completion of the audits.
Completion Schedule: These audits should be completed by May 31,1999.
Contact:
Questions regarding this audit plan should be directed to Rob Elliott at 301-415-1397.
Statistical Data Reporting: Hou.s expended for this audit, including preparation time, should be repoded under TAC number Originating Organization Information Organization. Responsibility: This audit plan was initiated by the Containment Systems and Severe Accident Branch (SCSB).
Resource Estimate: It is estimated that each audit will require approximately 240 hours0.00278 days <br />0.0667 hours <br />3.968254e-4 weeks <br />9.132e-5 months <br /> per audit (120 hours0.00139 days <br />0.0333 hours <br />1.984127e-4 weeks <br />4.566e-5 months <br /> per auditor, with 2 NRR representatives on each audit). The staff estimates approximately 40 hours4.62963e-4 days <br />0.0111 hours <br />6.613757e-5 weeks <br />1.522e-5 months <br /> at each audit site.
Other: It is anticipated that each audit team will consist of two members of SCSB and two contractor personnel.
Training: No specific training are associated with this audit.
References NRC Bulletin 93 02, " Debris Plugging of Emergency Core cooling Suction Strainers," dated May 11,1993.
5 owe
i DRAFT l
NRC Bulletin 93-02, Supplement 1," Debris Plugging of Emergency Core cooling Suction Strainers," dated February 18,1994 NUREG/CR-6224," Parametric Study of the Potential for BWR ECCS Strainer Blockage Due to LOCA Generated Debris" dated October 1995.
NRC Bulletin 95-02," Unexpected Clogging of Residual Heat Removal (RHR) Pump Strainer While Operating in Suppression Pool Cooling Mode," dated October 17,1995.
NRC Dulletin 96-03, " Potential Plugging of Emergency Core Cooling Suction Strainers by Debris in Boiling-Water Reactors" dated May 6,1996.
Regulatory Guide 1.82, Revision 2, " Water Sources for Long-Term Recirculation Cooling l
Following a Loss-of-Coolant Accident," dated May 1996.
1 3-I GL 97-04, " Assurance of Sufficient Net Positive Suction Head for Emergency Core Cooling and Containment Heat Removal Pumps," dated October 7,1997.
4 4
i t
1 J
l r
l; i
l 4
1 l
1 j
I l
6 mm, i
s c-n
DRAFT 4
Appendix-A Plant Familiarization a
wre: intorniarion in h!ue anti gray color is example inti, or options as aitabh.
L General Plant Data Plant Name:
i Containment Type:
Mark!!athit Vendor for Strainer:
Vendor for DH Analysis:
Vendor for Loads Analysis:
4
)
2.
Inventory of Maior Insulations Fibrous Particulate RMI Other Piping Type (TypeNol)
(TypeNol)
(TypeNol)
(Type'Vol)
Primary Piping -
r.
4 Reactor Shielding Cavity
- - s:
Special Structure /Cv.nponent Miscellaneous (
)
r:
(Units: Volume in W and Foll Area in ft")
3.
Debris Generation Model Used in the Analysis Method #1 - All [hbris in the Containment g/
yes/no Method #2 yerr.o Method #3 ye s/no Method #4 -- Not reviewed by Staff yc:mo A-1
- ime
~
DRAFT 4.
Drywell Transport Factors Used in the Analysis Transport Factor is assumed equal to 1 ye-Jno i
Used URG Transport Factors v
yesIno Plant Specific Calculations yesino 5.
Suppression Pool Transport Factors Used in the Analysis Transport Factor is assumed equal to 1 yes/no i
Used NUREG/CR-6224 Type Calculations v
yes/nc Plant Specific Calculations yes!no Note: A plant may use a combination of NUREG/CR-6224 calculations for some types of debris and a TF of 1.0 for other debris.
i 6.
Smtrees of Other Debris (Miscellaneous Debris)
Miscellaneous Debris Location Basis for Estimates i
Other Fibrcus Paint I
Rust
.+.2.
3 i
Sand / Concrete Dirt and Dust
. =
..d.
l Sludge f
i Other (
ea. FOAM
)
7.
Head Loss Estimation Vendor Correlation and Analysis Used g
yes:c Vendor LTR Enclosed yet. no Vendor LTR Prevlously Reviewed by Staff y
yes/no
. Vendor tested Exact Strainers with Insulation yte w 1
Plant Specific Analysis (e.g., URG Correlations) yes nc l
A-2 imme
~. _ _ _. _ _ _ _ _ -. _ _
L-DRAFT 8.
NPSH Calculations and Comparison with GL 97-04 L
Operator Throttling of ECCS Assumed v
Time at which throttled '
minutes Flow and Temp after Throttling used in Cales.
GPM/ oF Maximum Pool Temperature
'F 4
Assumed Containment Overpressure psi Staff reviewed the NPSH Calculation a
Reference No:
4 1
Date of Approval:
i j
9.
Suppression Pool Cleanliness Program (SPCP)
SPCP Part of Maintenance Rule (10 CFR 50.65) Program v
yesino SPCP Addressed NRCB 95-02
/
yes/no l
10.
Codes and Standards (Comparison with Licensing Basis /UFSAR)
Quality Assurance Requirements gf yesino 10 CFR Appendix-B gr yes/no ASME Certificate Required v
yes/no j-Materials j
Conform to ASTM Specifications v
Certified Material Test Reports are Provided v
Design / Fabrication Qualified ASME Section lit, Subsection NC v
Qualified ASME Section Ill, Class 2 y
Other (
)
' Welding Qualified to ASME Section IX v
Other_(
)
NDE per ASME Section ill Critical welds examined by liquid penetrant v
All Other Welds Visually Examined v
l Other (
)
V A-3 im*
DRAFT Appendix-B
~
Head Loss Estimate Calculations i
Note: It is assumed that these tables will be filled in by tin staf f. Licenste shoulii(nsure that such infisimation is available in tin lictnsee calculation and npiirts.
)
1.
Destruction Pressures Used Insulation Type Plant Staff Transco RMI Cal-Sil with Al Jacket l
K Wool Ternp-Matwith ss wire retainer Knaupf j
Jacketed Nukon j
Unjacketed Nukon j
Koolphen K j
MIRROR from Diamond Min K Other:
(
)
(
)
(
)
1 B-1
_=
DRAFT l
2.
Area of the Zone ofInfluence Used (or Equivalent L/D for Sphere 1 Insulation Type Break #1 Break #2 Break #3 Break #4 l
Plant Staff Plant Staff Plant Staff Plant Staff Transco RMI Cal-Sil with Al Jacket i
K-Wool Temp-Mat Knaupf 4
Jacketed Nukon Unjacketed Nukon Koolphen-K MIRROR RMI Min-K Other:
(
)
(
)
(
)
(
)
3 Volume of Debris Generated by the Break Insulation Type Break #1 Break #2 Break #3 Break #4 Plant Staff Plant Staff Plant Staff Plant Staff Transco RMI Cal-Sil with Al Jacket K-Wool Temp-Mat Knaupf Jacketed Nukon Unjacketed Nukon i
hoolphen-K MIRROR RMI Min-K Other:
(
)
(
)
(
)
(
)
If Breaks < 2. then Vendor Data Supports screening out rest of breaks v or X Plant analyses showed MLOCA's are not important v or /
B-2 imu
DRAFT 4.
Drvwell Debris Transport Fractions Used in the Analysis Insulation Type Break #1 Break #2 Break #3 Break #4 Plant Staff Plant Staff Plant Staff Plant Staff Transco RMI Cal-Sil with Al Jacket K-Wool Temp-Mat Knaupf Jacketed Nukon Unjacketed Nukon Koolphen-K MIRROR RMI Min-K Other:.
(
)
(
)
l
(
)
(
)
5 Wetwell Debris Transport Fractions Used in the Analysis insulation Type Break #1 Break #2 Break #3 Break #4 Plant Staff Plant Staff Plant Staff Plant Staff Transco RMI Cal-Sil with Al Jacket K-Wool Temp-Mat Knaupf Jacketed Nukon Unjacketed Nukon Koolphen-K MIRROR RMI Min-K Other:
(
)
(
)
(
)
~
(
)
B3 mm.
DRAFT 5.
Net Insulation Debris on the Strainer insulation Type Break #1 Break #2 Break #3 Break #4 Plant Staff Plant Staff Plant Staff Plant Staff Transco RMI Cal-Sil with Al Jacket K-Wool Temp-Mat Knaupf Jacketed Nukon Unjacketed Nukon Koolphen-K MIRROR RMI Min-K Other:
(
)
(
)
(
)
(
)
6.
Miscellaneous Debris Plant Est.
URG Recom Staff Estimate Debris Type Gen T. F.
Gen T.F.
Gen T.F.
Other Fibrous Paint Rust Sand / Concrete Dirt and Dust Sludge Other ( FOAM
)
Other (
)
B-4
DRAFT 7.
ECCS Flow Rate and Design Details lRHR #1lRHR #2[RHR #3lRHR #4l CS #1 l CS #2 i
Before Throttling Flow Rate (GPM)
Pool Temperature (oF)
Wetwell Pressure (psia)
NPSH Margin 4
After Throttling (Time:
min)
Flow Rate (GPM)
Pool Temperature (oF)
Wetwell Pressure (psia)
NPSH Margin l
8.
Strainer Flow Rates and Desien Details 1
l Str #1l Str #2 l Str #3 l Str #4 l Str #5 l Str #6 Previous Strainer Flow Rate Data Full Design 1
Full Single Failure Throttle Single Failure Throttle Design Outer Diameter Active Length Flange Diameter Plate Area Clean Head Loss Replacement Strainer Flow Rate Data I
)
Full Design Full Single Failure Throttle Single Failure Throttle Design Outer Diameter Active Length Plate Area (Effective)
Gap Volume Circumscribed Area Clean Head Loss Basis for Clean DH B-5 mmm i
DRAFT 9.
Strainer IIcad Loss Calculations Unthrottled Flow (sinele failure or design case): For common header plants design flow may result in worse head loss.
f Property Straher #1 Strainer #2 Strainer #3 Strainer #4 Strainer #5 Strainer #6 Plant Staff Plant Staff Plant Staff Plant Staff Plant Staff Plant Staff t
Circumsenbed Velocity :
i i
i i
j i
i i
Plate Velocity i
i i
i Temperature i
i i
i i
l Mass of Fibrous Debris i i
i 5
i i
i Volume of Fibrous Debrisi i
i r
i i
i
% Occupancy of Gap i
i i
i 5
i Area of Reflective Metallici i
i i
i i
i i
i i
(
K, i
i
[
i i
i i
Kn i
Mass of Corrosion Prod. -
i i
e i
f Correlation Head Loss i
i i
i i
a i
i
{
Bump-up Factors i
i i
i i
l i
i Paint Chips 5
i i
Rust i
i i
i i
i j
Sand i
i i
i i
i.
t l
Dirt / Dust i
i i
i i.
i i
Zinc i
i i
j Calcium-Silicate i
i i
i i
i i
i Net Debns Head Loss i
i i
i i
i i
i j
l Clean Head Loss i
i i
i i
i i
i i
i Total Head Loss i
i 5
i i
i i
i j
j NPSH Margin Left i
i i
~
I 1
i t
I B-6 iomm
. 1 DRAFT i
Throttled Flow:
i Property Strainer #1 Strainer #2 Strainer #3 Strainer #4 Strainer #5 Strainer #6 i
Plant Staff Plant Staff Plant Staff Plant Staff Plant Staff Plant Staff l
Circumscnbed Velocity i i
i i
?
i i
i Plate Velocity i
i 3
i
=
Temperature i
i i
i i
i Mass of Fibrous Debris.
5 i
s 3
g l
i i
3 3
Volume of Fibrous Debosi
=
l
% Occupancy of Gap
+
i i
3 E
j Area of Reflective Mebilici i
i K,
i i
i i
i i
5 i
i K,,
i i
i i
i i
[
3 3
3 l
Mass of Corrosion Prod. 5 i
Correlation Head Loss E
i l
Bump-up Factors i
i i
i E
[
Paint Chips i
i i
i 3
Rust 5
3 i
3 3
3 Sand i
i i
i i
5 i
i Dirt / Dust i
i i
=
i e
i i
+
Zinc 5
i i
i i
i i
j Calcium-Silicate E
=
i i
i i
i Net Debns Head Loss i
i i
i e
i i
Clean Head Loss i
i i
i i
i i
i I
Total Head Loss i
i i
i i
i i
NPSH Margin Left i
i j
j I
i i
l
,an B-7 i
l
j DRAFT j..
4 i
1 i
h j
10.
Overall Strainer Performance i
{
Str #1 Str #2 Str #3 Str #4 Str #5 Str #6 Strainer Plate Area increase Circumscribed Area increas 1
Volume Increase Hole Dimension Change j
Volume of Gap
{
DH Old (RG 1.82. Rev. O or 1)
}
DH New (RG 1.82, Rev. 2)
Cont. Over Pres Requirement
)
1 I
i l
a 1
I
.l 4
I 4
B-8
DRAFT Appendix-C Codes / Standards and Suppression Pool Cleanliness Program 1.
Does the Strainer Design, Material Procurement and Manufacturing meat Codes and Standards in the following Deciplines Quality Assurance Reauirements 10 CFR Appendix-B ASME Certificate Required Materials Conform to ASTM Specifications Certified Material Test Reports are Provided Deslan/ Fabrication Qualified ASME Section Ill, Subsection NC Qualified ASME Section lil, Class 2 Other (
)
Welding Qualified to ASME Section IX Other (
)
NDE per ASME Section ill Critical welds examined by liquid penetrant All Other Welds Visually Examined Other (
)
2.
Has the licensee incorporated its suppression pool cleanliness program into the scope of its maintenance rule (10CFR50.65) program?
If the answer to number 1 above is yes, then O
What goals have been established by the licensee for suppression pool cleanliness? Strainer cleanliness?
O How is the licensee monitoring its suppression pool / strainer cleanliness goals?
O If monitoring is not required, what preventative maintenance is the licensee performing to ensure that the suppression pool and associated strainers can perform their intended safety function?
O What is the frequency of monitoring or preventative maintenance (as applicable to the licensee's program)?
C-1 iema -
DRAFT O
When was the last assessment of suppression pool performance /gcals or preventative maintenance performed, and what were the licensee's findings?
O What related industry experience was considered in the last assessment and what were the licensee's conclusions relative to applicability of this experience to their plant?
O What adjustments, if any, were made to the licensee's programs based on the last assessment?
O Has the licensee considered the affect of its maintenance or monitoring activities on total availability of safety systems?
O Has the licensee taken steps to minimize unavailability of safety systems due to suppression pool / strainer monitoring or maintenance activities?
O When is the next assessment of performance / goals or preventative maintenance scheduled?
If the answer to number 1 above is no, what is the licensee's basis for not including the suppression pool and/or suction strainers in the scope of its maintenance rule activities?
In addition, did the licensee establish a suppression pool cleanliness program as requested in NRC Bulletin 95-027 O
How is the licensee ensuring the operability of the ECCS relative to ensuring an adequately clean suppression pool and ECCS suction strainers?
O How is the licensee administratively controlling its suppression pool / strainer cleanliness program?
0 What criteria has the licensee established for suppression pool and strainer cleanliness?
O What is the licensee's planned frequency for cleaning the suppression pool and strainers?
C-2
Project No. 691
. Boiling Water Reactor Owners Group cc:
Thomas J. Rausch, Chairman W. Glenn Warren Boiling Water Reactor Owners' Group Southern Nuclear / Georgia Power Commonwealth Edison Company E.1 Hatch Nuclear Plant Nuclear Fuel Services PO Box 1295 M/C B052 1400 Opus Place,4th Floor ETWill Birmingham, AL 35201 Downers Grove,IL 60515 Carl D. Terry Dennis B. Townsend Vice President, Nuclear Engineering GE Nuclear Energy Niagara Mohawk Power Corporation M/C 182 Nine Mile Point-2 175 Curtner Avenue PO Box 63 San Jose, CA 95125 Lycoming, NY 13093 Drew B. Fetters -
Thomas A. Green PECO Energy GE Nuclear Energy Nuclear Group Headquarters Mail Code 182 MC 62C 3 175 Curtner Avenue 965 Chesterbrook Blvd.
San Jose, CA 95125 Wayne, PA 19087 John Hosmer -
Commonwealth Edison Executive Towers,4th Floor 1400 Opus Place Downers Grove,IL 60515 George T. Jones Pennsylvania Power & Light MC A6-1 Two North Ninth Street Allentown, PA 18101 Lewis H. Sumner Southern Nuclear / Georgia Power E. I. Hatch Nuclear Power Plant 40 Inverness Parkway PO Box 1295 Birmingham,GA 35201 John Kelly New York Power Authority 14th Floor Mail Stop 14K Centroplex Building 123 Main Street White Plains, NY 10601
. - - - -