ML20249A530
| ML20249A530 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 06/15/1998 |
| From: | Schopfer D SARGENT & LUNDY, INC. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| 9583-100, NUDOCS 9806170015 | |
| Download: ML20249A530 (15) | |
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Don K. Schopfer Senior Vice President 312 709 6078 l
June 15,1998 Project No. 9583-100 l
. Docket No. 50-423 Northeast Nuclear Energy Company Millstone Nuclear Power Station, Unit No. 3 Independent Corrective Action Verification Program United States Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555 I have enclosed the following discrepancy reports (DRs) identified during our review activities for the ICAVP. These DRs are being distributed in accordance with the Communications Protocol, PI-MP3-01.
I have enclosed the following three (3) DRs for which the NU resolutions have been reviewed and accepted by S&L.
DR No. DR-MP3-0328 DR No. DR-MP3-0686 DR No. DR-MP3-0726 t/
Please direct any questions to me at (312) 269-6078.
/
Yours very truly, t
D.T f -d D.K.S opfer I.
SeniorVice President and
.obdOO ICAVP Manager DKS:spr Enclosures Copies:
E. Imbro (1/l) Deputy Director, ICAVP Oversight T. Concannon (1/1) Nuclear Energy Advisory Council J. Fougere (1/l) NU m%evgiber\\98WO615a4w 9906170015 990615 '
PDR ADOCK 05000423 P
PDR 55 East Monroe Street
- Chicago. IL 60603-5780 USA
- 312 269 2000
I Northeast Utilities ICAVP DR No. DR44P3-0328 millstone Unit 3 Discrepancy Report Review Group: Syelem DR RESOLUTION ACCEPTED Review Element: Syolem Design j
Diecipline: Mechanical Design g
F---
, my Type: Component Date O*
systemfProcese: HVX NRC signiacance M 3 Date FAXad to NU:
Date Published
- 1W23/97 r-. :i; SLCRS and ABVS Filter Unit Drain Valves Descripasea' During review of the component data for the Supplementary Leak Colledion and Release System (SLCRS) filter units (3HVRTLT3A/38) and the Auxiliary Building Ventilation System I
(ABVS) exhaust filter units (3HVRTLT1 A/1 B) a discrepancy J
regarding the safety and seismic classification of the isolation
)
valves in the filter unit drain lines was identified.
The SLCRS and charging pump, component cooling water pump and heat exchanger exhaust ventilation system (ABVS) are classified as ESF Filter systems per FSAR Section 6.5.1
)
FSAR Section 6.2.3.1 states that the SLCRS is classified QA Cate00 ) I, Safety Class 3, and Seismic Cate9ory I. FSAR Sedion 9.4.3.1 states that the auxiliary building filtration units are Safety Class 3.
FSAR Section 3.2.3 and FSAR Table 3.2-1 indentify the ESF filtration trains as QA Category 1, Safety Class 3 components.
FSAR Table 6.5-1 states that the systems are in essential compliance with Regulatory Guide 1.52, Rev. 2 position C.2.c in that all components are seismically qualified. FSAR Table 1.8-1 states that the systems are in compliance with Regulatory Guide 1.52, Rev. 2 and does include the exception / clarification to position C.2.c contained in FSAR Table 6.5-1.
Regulatory Guide 1.52, Rev. 2, position C.2.c requires that all components of an engineered-safety-feature atmosphere cleanup system should be designated as Seismic Category I if failure of a component would lead to the release of significant quantities of fission produds to the working or outdoor environments.
P&lD EM-148E shows valves 3HVR-V964, V965, V966, V967, V968, and V969 in the drain lines for SLCRS filter unit 3HVRTLT3B and valves 3HVR-V970, V971, V972, V973, V974, and V975 in the drain lines for SLCRS filter unit 3HVRTLT3A.
P&lD EM-148A shows valves 3HVR-V988, V989, V990, V9991, V992, and V993 in the drain lines for ABVS filter unit 3HVRTLT1B and valves 3HVR V994, V995, V996, V997, V998, and V999 in the drain lines for ABVS filter unit 3HVRTLY1 A.
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The valves maintain the pressure and leakage integrity of the i
filter units and prevent unfiltered air from bypassing the HEPA and charcoal filter sodions. Based on this and the above n' x fc the ;d;= 2-M M '-- *: ' = O^ C ^ g!
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_-------.------N.---.-------'-----------
1 Northeast Utilities ICAVP DR No. DR-MP3-0328 Millstone Unit 3 Discrepancy Report Safety Class 3, Seismic Category I components.
The Plant Design Data System (PDDS) database identifies the valves as QA Category 2 components. The valve description #
shown in PDDS is VGF015-N-4.
The PMMS database identifies the valves as non-seismic, non-category I components.
Specification 2282.050-153 identifes valve type VGF015-N-4 as a 2.5" ANSI B31.1 Class 4 gate valve.
Review Valid invalid Needed Date initiator: Stout, M. D.
O O
O 1o*S7 VT Lead: Nei, Arthony A O
O O
o/3/87 VT Mgr: Schopfer, Don K O
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ot13'87 IRC Chmn: Singh, Anand K O
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1ot s/97 Date:
INVAUD:
Date: 6/15/98 RESOLUTION: First Response NU has concluded that the issue reported in Discrepancy Report, DR-MP3-0328, does not represent a discrepant condition. The piping and drain valves that are in question are subject to the requirements of Reg. Guide 1.52. As indicated on P&lD EM-148A note 4, the valves and associated drain system piping have been seismically supported and qualified which ensures the structural integrity of the system. Also, refer to the attached Pipe Stress Analyses for Aux Building floor and equipment drains.The drain valves are ancillary passive components and are non-safety related but seismically supported. Further, the normally closed valves do not require mechanical movement for SLCRS and Auxiliary Building HVAC (HVR) to perform their intended safety functions.There is no credible failure of these passive valves that would impose operational limitations to the system or would result in a loss of the capability of the SLCRS and HVR to perform their intended safety function. This is consistent with MEPL determinations MP3-CD-1027 and 1035. The exception to this are the drain valves off of the moisture separators. These valves are normally open, however, they are connected to the upstream side of the filter and discharDe to the radioactive waste sump, located within the SLCRS boundary. Consequently, any
- eakage up the drain would still pass through the filter. Therefore, PDDS and PMMS are correct in categorizing the drain valves as QA CAT 2 and the filter as CAT 1 safety related but seismically supported. Significance level criteria do not exist as this is not a discrepant condition.
Attachments:
12179-NP(B)-X54000, Pipe Stress Analysis: Floor and Equipment Drains Auxiliary Building 12179-NP(B) X54001, Pipe Stress Analysis: Floor and Printed 6/15/98 4 45.59 PM Page 2 of 5
Northeast Utilities ICAVP DR No. DR-MP3-0328 Millstone Unit 3 Discrepancy Report Equipment Drains Auxiliary Building 12179-NP(B)-X54002, Pipe Stress Analysis: Floor and Equipment Drains Auxiliary Building 12179-NP(B)-X54003, Pipe Stress Analysis: Floor and Equipment Drains Auxiliary Building l
12179-NP(B)-X54004, Pipe Stress Analysis: Floor and j
i Equipment Drains Auxiliary Building MEPL Determination MP3-CD-1035, section 4.03, 3HVR*FLT3A/B Drain Valves MEPL Determination MP3-CD-1035, Attachment 3, Non-QA Component Listing MEPL Determination MP3-CD-1027, section 4.02, 1
3HVR*FLT1 A/B Drain Valves I
MEPL Determination MP3-CD-1027, Attachment 3, page 3-6, Non-QA Component Listing Second Response (M3-IRF-01831) l NU has concluded that the Discrepancy Report, DR-MP3-0328, has identified a condition not previously discovered by NU which requires correction.
CR M3-98-0922 was initiated to document the discrepancies identified in DR-MP3-0328 and DR-MP3-0642 regarding the classification of the ABVS/SLCRS filter units and filter unit fire protection system. The CR M3-98-0922 corrective action plan requires a revision to MEPL MP3-CD-1027 and MEPL MP3-CD-1035 to clarify the filter unit drain line determination with regard to pressure and leakage integrity. MEPL MP3-CD-2365 was approved on 4/9/98 to supplement MEPL MP3-CD-1027 and j
MEPL MP3-CD-1035. MEPL MP3-CD-2365 concluded that the i
drain valves are Non-QA.
The basis for the determination is that the drain valves are normally closed and are not required to function during an accident. The OPS Valve lineup lists the valves as closed and the valves would only be opened following a delu0e from the fire protection system. There is no requirement and no benefit to performing leak testing of these valves. These drain lines and associated valves have been seismically qualified. Therefore, there is no credible faliure mechanism of the valves as a result of a seismic event or a design basis accident.
In addition, the valves have been designed, fabricated, tested, certified, inspected and installed in accordance with ANSI B31.1 per the original purchase specification 2282.050-153 " Cast Stainless Steel Valves-21/2 inch and Larger". The valve also conforms to ANSI B16.5 pressure and temperature ratings. This is consistent with damper requirement outlined in ANSI N509-1976, section 5.9.1, c and 5.9.3. which require class A dampers to meet the requiretrient of ANSI B31.1, Therefore, these valves meet all the requirements of the purchasing specification and the standards set forth in N509-1976 and verifies that valves have been proper 1y fabricated and installed and the system will perform in accordance with specification requirements.
Printed 6/1548 4 45:50 PM Pape 3 or 5 u_____-_______-_-_
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Northeast Utilities ICAVP DR No. DR-MP3-0328 Millstone unit 3 Discrepancy Report NU considers the issues identified in DR-MP3-328 to be a significance level 4 based on clarification to MEPL MP3-CD-1027 and MEPL MP3-CD-1035. As stated in M3-IRF-00557, there is no credible failure of these passive valves that would l
impose operational limitations to the system or would result in a loss of the capability of the SLCRS/ABVS to perform their intended safety function.
i Attachments:
CR M3-98-0922 MEPL MP3-CD-2365 Third Response (M3-IRF-02361) l NU has concluded that this issue reported in DR-MP3-0328 has identified a CONFIRMED SIGNIFICANCE LEVEL 3 condition which requires correction.
Based on a telephone conference on 6/9/98, NU is revising our response to this unresolved issue. NU has written CR M3 2866 to address this discrepancy. For stress and support purposes, the filter units' drain valves and connected piping are considered part of the Auxiliary Bldg. floor drain system. The approved corrective action for this CR will result in a modification per the DCM that will revise MEPL MP3-CD-2365 to revise the QA classification of the drain valves and piping connected to filter units 3HVR*FLT1 A/B,2A/B, and 3A/B as necessary to support the safety related function of the units.
(note: MP3-CD-2365 was issued to revise MP3-CD-1035 and MP3-CD-1027 on the specific topic of the drain valves). The modification will also revise related design documents.
Operability Determination No. MP3-076-98, which was PORC approved on 6/10/98, justifies system operability for startup.
Attachments:
CR M3-98-2866 OD No. MP3-076-98 Previously identified try Nu? O Yes (9) No Non Discrepent Condition?O Yes (#1 No Resolution Pending?O Ya @ No Resoeuuanunresoeved70 Y=
@ No Review Acceptable Not M ;W Needed Date VT t.eed: Neri. Anthony A VT Mgr: schopfer, Don K 1RC Chmn: singh, Anand K Date:
6/15/98 st. comments: Comments on First Response FSAR Table 3.2-1 st&tes that the ESF filter units are ANS Safety I
Class 3 components. Since the valves maintain the pressure and j
leairage integrity of the filter units and prevent unfiltered air from j
bypassing the HEPA and charcoal filter sections they should be classified the same as the ESF filter units.
Printed 6/15/98 4 46.00 PM Page 4 of s
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Northeast Utilities ICAVP DR No. DR-MP3-0328 umstone unit 3 Discrepancy Report MEPL Determination MP3-CD-1035 and MP3-CD 1027 do not address this function of the valves.
Comments on Second Response MEPL Determination No.: CD-2365 dated 4/9/98 does not adequately address the safety function of the filter unit drain valves. On page 3 of the MEPL in response to question Ill.
'Does the item, activity, or software support the system safety function?" the response was no "... The other valves (HVR) are used as filter unit drain isolation valves. They do not have a direct affect on the safety function of the Units." The response should have been yes they do support the safety function of the unit. The I
drain valves prevent unfiltered air bypassing the charcoal filters.-
l Based on a yes response to question til, the valves are classified l
as Safety Related, QA Cat I per VI.b on pg 5 Since the safety classification of the drain valves do not meet the licensing basis this is considered to be a significance level 3 discrepancy.
This DR is unresolved.
Comments on Third Resonse (M3-IRF-02361)
The corrective action for CR M3-98-2866 to umrade the drain valves to QA status addresses the unresolvea issue.
Agree that based on OD #MP3-076-98 that this is a Significance Level 3 Discrepancy.
Printed 6/15/96 4-4600 PM Page 5 of 5
Northeast Utilities ICAVP DR No. DR MP3-0686 Millstone Unit 3 Discrepancy Report l
Review Group: System DR RESOLUTION ACCEPTED Review Element: Systern Design p
Diecipline: Mechanical Design Ow Discrepancy Type: Calculation System / Process: HV/.
i NRC Significance level: 3 Date faxed to NU:
l Date Published: 12/8/97 Discrepancy: ABVS Filter Unit Bypass Leakage i
==
Description:==
During the review of calculation P(B)-1105 Rev. O which quantifies the charcoal filter bank bypass leakage and P&lD EM-148A-24 a discrepancy regarding filter bypass leakage paths was identified.
The pressure in the inlet plenum of the auxiliary building exhaust filter units 3HVR*FLT1 A/1B is maintained by pressure controller 3HVR*PIC104A/B. The pressure controller modulates inlet vane dampers 3HVR* MOD 140A/B for exhaust fans 3HVR*FN6A/B to maintain the pressure at 1.5 iwg per calculation NSP-097-HVR.
With the inlet plenum maintained at a positive pressure there is a potential for unfiltered air to bypass the filter units through isolation dampers 3HVR*AOD44A/B. Calculation P(B)-1105 does not address this bypass leak path.
Review Valid invalid Needed Date instietor: Stout, M. D.
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O 11' 7/S7 i
VT Lead: Nort, Anthony A O
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is/24/97 l
VT Mgr: schopfer, Don K O
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2/t/97 j
1RC Chmn: singh, Anand K O
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$2/4/97 Date:
1 INVALID:
Date: 6/11/98 RESOLUTION: First Response (M3-IRF-01376)
NU has concluded that Discrepancy Report DR-MP3-0686 has i
identified a condition not previously discovered by NU which
)
requires correction.
The leak path through dampers 3HVR*AOD44A/B bypassing the ABVS filter units was missed and should have been included in l
calculation P(B)-1105.
Originally, the results of P(B)-1105 and calculation P(B)-1173, which identified additional leak paths bypassing the SLCRS boundary, provided inputs to radiation protection calculation UPuH39. W5M Amendment 59 changed the containment n6 sal operating pressure from subatmospheric to atmospheric, UR(B)-439 was superseded by calculation 88-019-96RA. This calculation is the subject of an evaluation being tracked by AR 97024017.
The discrepancy reported in this DR is part of a more comprehensive problem that was identified by CR M3-97-3274.
Printed 6/15/9610 53.50 AM Page 1 of 6
Northeast Utilities ICAVP DR No. DR-MP3-0686 Millstone Unit 3 Discrepancy Report This CR was initiated to identify potential bypass leakage to the environment caused by negative pressures in the areas outside the SLCRS boundary, causing leakage through isolation dampers. The corrective action to the CR resulted in the general evaluation of SLCRS boundary bypass leakage and impact on the DBA / LOCA dose limits tracked by AR 97024017-03. A specific reference to bypass leakage through 3HVR*AOD44A/B was added to AR 97024017-03, which is scheduled to be completed before startup.
I NU concurs that this discrepancy is a Significance Level 3.
Attachments:
CR M3-97-3274 with corrective action plan.
Second R'.sponse (M3-IRF-02071)
NU has concluded that the issue reported in DR-MP3-0686 has identified a PREVIOUSLY IDENTIFIED condition which will be corrected.
SarDent and Lundy's acceptance of NU's previous response, as submitted via M3-IRF-01376, was based on our determination at that time that the described condition was not previously identified and was a valid discrepancy. As a result of additional research, NU has changed this position and this response provides the basis for revised status.
A time line and explanation of those intemal activities and events which led to NU's full understanding of this issue is attached (see Attachment A). The attached chronology of events relating to this DR has its roots in evaluations being conducted in 1995 relative to the issue of Overiap Testing. An operational occurrence in April of 1997, wherein the failure of a damper created an excessive negative pressure condition in an area adjacent to a SLCRS boundary, initiated a series of events which culminated in the initiation of a Condition Report in September of 1997. One of the approved corrective actions for the CR requires Engineering to " perform an Engineering Evaluation to further evaluate potential SLCRS boundary bypass leakage and impact on the DBA LOCA dose limit.". The trail of events leading to this corrective action provides evidence that the unit's System and Design Engineering staff recognized the larger implications of smaller events well in advance of the "end-of-discovery" date for the Wave 11 Systems that are involved in the conditions described in this CR.
As reported in M3-IRF-1376, the issue of bypass leakage through isolation dampers 3HVR*AOD44A/B is related to NU's investigation of a larger, more General problem. On 4/9/97, CR M3-97-1017 identified a problem in which damper failure resulted in a challenge to the operability of the SLCRS System.
The generic implications of this CR were communicated to the design engineering supervisor by the system engineer (see Attachment B). In this e-mail a concem was expressed that failure of the non safety fans could cause a neoative pressure in Printed 6/159610:53:51 AM Page 216
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I
l Northeast Utilities ICAVP DR No. DR-MP3-0686 Millstone Unit 3 Discrepancy Report areas adjacent to the SLCRS boundary. This led NU systems engineers to consider related scenarios in which malfunction of non-safety related fans peripheral to SLCRS could result in unfiltered bypass leakage. On 8/8/97, CR M3-97-2560 was written to address necessary procedure changes for overlap testing of fans. While reviewing corrective actions for M3 2560, and with overall knowledge of CR M3-97-1017, the system engineer initiated CR M3-98-3274 to fully address his concems.
Further investigations revealed that there were several potential filter bypass pathways associated with leakage through closed SLCRS boundary dampers that were not evaluated in the (then) current LOCA dose analyses. Engineering Record Correspondence 25212-ER-98-0168, MP3 SLCRS Bypass Leakage Analysis Scenarios, (copy attached) addresses effects on dose analyses from bypass leakage listed in calculations 98-ENG-01554M3 and 98-ENG-01595M3, (copies attached) which were prepared to identify all systems interfacing with the secondary containment negative pressure boundary following a LOCA.
j Sargent and Lundy's most recent correspondence on this DR accepted NU's response with the understanding that " the calculations that determine the bypass leakage through dampers 3HVR*AOD44A/B and the impact this leakage has on offsite and control room dose are needed to determine the final significance level". While significance levels have no meaning to previously discovered items, NU recognizes the need to provide additional documentation along with this amended response.
Attachments:
Calculation No. 98-ENG-01554M3 Unfiltered Leakage From SLCRS Boundary Calculation No. 98-ENG-01595M3 Unfittered Leakage From SLCRS Boundary-Non Class 1 Equipment Trips Attachment A Chronology of Events Attachment B Copy of e-mai! correspondence from D.A. Presutti Engineering Record Correspondence 25212-ER-98-0168 CR M3-971017 CR M3-97-2560 Previously identifled by Nu? O vee (9) No Non "-,"Condation?O Yee (9) No r
Resolution Ponding?O vee @ No noeoeueionunresoeved?O vee @ No neview initiator: stout, M D.
~
VT Lead: Nort, Anthony A
. VT Mgr: schopfw, Don K lac cevnn: singh, Anand K Dete:
6/11/98 SL comments: Comments on First Response NU's response is acceptable.
Printed 6'15S610.s3 51 AM Pege 3 of 6
Northeast Utilities ICAVP DR No. DR-MP3-0686 Millstone Unit 3 Discrepancy Report The DR is classified as Resolution Pending as the calculations that determine the bypass leakage through dampers 3HVR*AOD44A/B and the impact this leakage has on offsite and control room dose are needed to determine the final significance level.
Comments on Second Response (M3-IRF-02071)
Disagree with NU's response that damper leakage was previously identified. It is not apparent from the information provided in NU's response that the impact that leaka0e thru damper 3HVR*AOD44A/B has on offsite (10CFR100) dose and control room (10CFR50 Appendix A GDC 19) dose was previously identified by NU.
OIR 430 (dated July 11,1996) involves identification of SI si0nal for fan 3HVQ-FN2 trip and failure to test fan 3HVQ-FN1 during 'B' train Si testing. The AR 96027116 does not address evaluation of damper leakage OIR 456 (dated July 15,1996) involves identification of SI signal for fan 3HVQ-FN2 trip. The AR 96027167 does not address evaluation of damper leakage.
CR M3-971017 (initiated 4/9/97) involved the potential for failure i
of dampers associated with fans 3HVQ*FNSA and 3HVQ*FN6A to l
result in a negative pressure in an area outside of the SLCRS boundary and lead to unfiltered release at ground level. The related corrective action of AR # 97008215-03 was ' evaluate if any supply, retum or recirc damper failure or alignment for fans 3HVQ'FNSA/B and FN6A/B would have an affect on SLCRS Boundary or SLCRS draw down. Initiate EWR if system modifications are needed and justified.' The CR and AR does not address evaluation of other damper leakage on offsite and control room dose levels.
E-Mail re CR M3-97-1017 (dated 4/10/97) addresses concern regarding the failure modes of the fans, which are outside the SLCRS boundary causing a greater negative that SLCRS. The e-mail was sent when CR M3-97-1017 was transferred to Design.
The corrective actions for CR M3-97-1017 did not address failure modes of fans outside the SLCRS boundary.
CR M3-97-2560 (initiated 8/8/97) addresses surveillance testing of fans 3HVQ*FNSA/B,3HVQ*FN6A/B,3HVQ* ACUS 1A/B and 3HVQ* ACUS 2A/B not meeting GL 96-01 requirements. The corrective action for this CR does not address evaluation of the impact of damper leakage on offsite and control room dose levels.
CR M3-97 3274 (initiated 9/27/97) addresses failure of exhaust fan 3HVQ-FN2 to trip and potential to create a negative pressure in areas adjacent to the SLCRS boundary (discovered during GL 96-01 testing performed to close out OIR 430 & 456):
- Deportability Determination dated 10/31/97: addresses impact of leakage due to fan 3HVQ-FN2 continuing to run on 10CFR100 site boundary doses. Impact on 10CFR50 Appendix A GDC 19 Printed 6/15/9610M51 AM Page 4 of 6
Northeast Utilities ICAVP DR No. DR-MP3-0686 Millstone Unit 3 Discrepancy Report control room dose limits not addressed in deportability determination.
- Generic implications block #2 "Further investigation indicates that there are other non-safety related SLCRS boundary fans which could be running during an accident and result in bypass to the environment. These fans include : 3HVR-FN8NB, 3HVR-FN9, 3GWS-FN1NB, 3HVR-FNS, 3HVR-FN7, 3HVQ-FNINB. It is recommended that an Engineering Evaluation be prepared to document the review and its results of all SLCRS boundary fans for any potential bypass leakage to the environment and its impact on the DBA LOCA dose limits."
- AR # 9702417 03 ' Based on RAB calculation No. 88-019-96RA, perform an Engineering Evaluation to further evaluate potential SLCRS boundary bypass leakage and impact on the DBA LOCA dose limits. This eval will address past assumptions made in superseded RAB calculations UR(B)-227 and UR(B)-439 regarding the effect of the various fans contiguous with the SLCRS boundary'[AR assignment dated 11/08/97]. The 3 calculations noted are for EAB and LPZ doses so it is not apparent that the impact on control room dose would have been addressed. AR 9702417-03 was revised to include the statement
" Address bypass leakage through 3HVR*AOD44A/B identified in ICAVP DR-MP3-0686".
SLCRS Bypass Leakage through Ducts and Dampers / SLCRS J
Boundary Fans Status (dated 1/3/98) Appears to be related to AR j
9702417-03 and contains a listing of faris and dampers. Table j
includes damper 3HVR*AOD44NB but not fan 3HVR*FN13NB that is the driving force for leakage through this damper. It is not apparent that leakage thru this damper would have been addressed.
j Calculations 98-ENG-01554M3, Rev. O and 98-ENG-01595M3, Rev. O identify the release point for the unfiltered leakage thru damper 3HVR*AOD44A/B as the turbine building stack. Based on the response to DR-MP3-0566, the release point would be near j
the missile hood on the auxiliary building roof.
1 Based on the corrective actions for CR M3-3274 NU was on the path to address the impact of damper bypass leakage on EAB and LPZ dose levels (10CFR100) prior to DR-MP3-0686 but after the 7/12/97 end of discovery date. The 113 cfm leakage thru damper 3HVR*AOD44NB is small in comparison to the 1402 cfm NU identified thru the other dampers. The inclusion / exclusion of leakage thru damper 3HVR*AOD44NB would not have changed the conclusion of NUs analysis.
Based on the above it is not clear that NU was on the path to address the impact of damper bypass leakage on control room dose levels prior to the 7/12/97 end-of-discovery date or DR-MP3-0686. The results of calculation UR(B)-450, Rev. O show that the 113 cfm leakage thru damper 3HVR*AOD44A/B has a small effect on control room operator dose and would not have resulted in GDC 19 limits beitsg exceeded Therefore. this is considered to be a level 3 discrepancy as Printed 6/15/9810.53:51 AM Page 5 or 6
Northeast Utilities ICAVP DR No. DR-MP3-0686 Millstone unit 3 Discrepancy Report unGitered bypass leakage thru damper 3HVR*AOD44A/B was not identified by NU prior to the DR or the 7/12/97 end of discovery
- date, in a telephone call on June 11,1998 NU has concurred with the level 3 classification.
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Northeast Utilities ICAVP DR No. DR-MP3-0726 milistone Unit 3 Discrepancy Report Review Group: system DR RESOLUTION ACCEPTED Review Element: system Design g
Diecipline: Mechenical Design Om Discrepancy Type: ceiculation gg systenVProcess: HVX l
NRC Significance level: 4 Date faxed to NU:
Date Published: 12/21/97 D6screpency: ESF Filter Unit Damper Leakage
==
Description:==
During review of the supplementary leak collection and release l
system (SLCRS) and auxiliary building ventilation system (ABVS) filter unit isolation dampers a discrepancy regarding damperleakage was identified.
FSAR Table 1.8-1, Reg. Guide 1.52, Rev. 2, Position C.3.p exception states " Damper leakage will not impact on the air cleaning effectiveness of the ESF systems." A calculation that determines the damper leakage allowable to meet air cleaning effectiveness requirements could not be located.
Review Valid invalid Needed Date initiator: Stout, M. D.
O O
O 1/2n/97 VT Lead: Neft, Anthony A B
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12/s/97 VT Mgr: schopfer, Don K B
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12/1i/97 IRC Chmn: singh, Anand K O
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$ 2/11/97 i
Date:
INVAUD:
Date: 6/10/98 RESOLUTION: First Response NU has concluded that the Discrepancy Report, DR-MP3-0726, has identified a condition not previously discovered by NU which requires correctinn.
Calculations P(B)-1173, " Air Leakage Through the SLCRS j
System isolation Dampers," and P(B)-1105 " Quantify Charcoal l
Filter Bank Bypass Leakage During Accident Modes of Operation," provide input to radiological calculation UR(B)-439 "LOCA DOSES to EAB & LPZ Assuming Containment Leakage I
is into Either the ESF MSV or Aux Building," which was l
superseded by calculation 88-019-96RA "EAB and LPZ Doses j
from a Millstone Unit 3 LOCA." Calculation 88-019-96RA I
determined the thyroid dose at the site boundary due to damper leakage.
CR M3-97-3274 was initiated on 9/27/97 to identify potential SLCRS bypass leakage to the environment. CR M3-97 3274 corrective action requires an En0ineering Evaluation of potential SLCRS boundary bypass leakage and impact on the DBA LOCA dose limits. The corrective action is required to be comoleted prior to startup.
NU concurs with the Significance Level 4 as determined by DR-Pnnted 6/15/9810.s4.07 AM Page 1 of 3 J
Northeast Utilities ICAVP DR No. DR-MP3-0726 Millstone Unit 3 Discrepancy Report MP3-0726. The Engineering Evaluation will provide technical justification for FSAR Tabie 1.8-1 exception to Reg. Guide 1.52, Rev. 2 position C.3.p. The evaluation will quantify the damper leakage and determine whether the damper leakage will have impact on the air cleaning effectiveness of the ESF systems.
In addition, DR-MP3-0686 identifies a discrepancy with regard to calculation P(B)-1105 not addressing the leak path through dampers 3HVR*AOD44A/B which bypasses the ABVS filter units. M3-IRF-01376 response to DR-MP3-0686 identified the CR M3-97-3274 corrective action to correct the discrepancy.
Attachments:
CR M3-97-3274 Second Response (M3-IRF-02235)
NU has concluded that this issue, reported in DR-MP3-0726, has identified a PREVIOUSLY IDENTIFIED condition which will be corrected.
I Sarge:J and Lundy's acceptance of NU's previous response, as submitt6d via M3 IRF-01490, was based on our determination at that time that the described condition was not previously l
identified and was a valid discrepancy. As a result of additional research, NU has changed this position and this response provides the basis for a revised status.
A time line and explanation of those intemal activities and events which led to NU's full understanding of this issue is attached (see Attachment A). The attached chronolegy of events relating to this DR has its roots in evaluations being completed in 1995 relative to the issue of Overiap Testing. An unexpected operational occurrence in April of 1997, wherein the failure of a damper created an excessive negative condition in an area adjacent to a SLCRS boundary. This initiated a series of events which culminated in the initiation of a Condition Report in September of 1997, wherein one of the approved corrective actions requires Engineering to " perform an Engineering Evaluation to further evaluate potential SLCRS boundary bypass leakage and impact on the DBA LOCA dose limits.". The trail of events leading to this corrective action provides evidence that the unit's System and Design Engineering staff recognized the larger implications of smaller events well in advance of the "end-of-discovery" date for the Wave il Systems that are involved in the conditions described in this CR.SarDent and Lundy's most recent correspondence on this DR accepted NU's response with the understanding that "The DR is classified as Resolution Pending as the results of the Engineering Evaluation noted in the response are needed to determine the final significance level."
While significance levels have no meaning to previously discovered items, NU recognizes the need to provide additional documentation along with this ammended response. For this reason, we have included a copy of DCR M3-98-029, recently PORC approved, to credit operator actions at one hour, post.
LOCA. to ensure that license and reaulatory limits, applicable to Prtrded 64 MI610 s4 08 AM Page 2 of 3
Northeast Utilities ICAVP DR No. DR-MP3-0726 Millstone Unit 3 Discrepancy Report Control Room and Technical Support Center dose consequences, are not exceeded. While implementation of this design change awaits NRC approval of a Proposed License Amendment Request, our evaluation has determined that offsite dose (EBZ and LPZ) limits remain below license levels with no credit assumed for operator intervention.
Please note that this issue is closely related to DR-MP3-0686.
NU's response to DR-686, given in M3-IRF-02071, includes calculations 98-ENG-01554M3 and 98-ENG-01595M3 which account for unfiltered leakage from SLCRS boundary.
Attachments:
DCR M3-98-029 MP3 SLCRS Bypass Leakage Project Attachment A Chronology of Events Previously identifled by NU7 O Yes (#1 t,o Non Discrepent Condition?O Yes rG) No naaution P.ndine70 va @ No RuolutionUnruolved70 va @ No
- n. view ACCePteble Not A -
Needed Date se D.
VT Leed: Nerl, Anthony A VT Mgr: schopfer, Don K sin 0, Anand K h
IRC Chmn:
Date:
6/10/98 st. Comments: Comments on First Response NU's response is acceptable.
The DR is classified as Resolution Pending as the results of the
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Engineering Evaluation noted in the response are needed to
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determine the final significance level.
Comments on Second Response (M3-IRF-02235)
NU's response does not address the Reg. Guide 1.52 Rev. 2, Position C.3.p FSAR exception nuted in the DR. DCR M3-98-029 attached to NU's response addresses leakage thru secondary l
containment boundary dampers. It does not address if the leakage values meet the FSAR and ANSI N509-1976 requirements.
(
l Since this involves a clarification of statements in the FSAR that does not impact the ability of the system to perform its function this is considered a level 4 discrepancy.
f Printed 6/15/9610MoS AM Pe0* 3 of 3