ML070780367

CR-PNP-1996-00396, High Mitrate Levels Exists in the Tbccw System

ML070780367
Person / Time
Site:	Pilgrim
Issue date:	09/24/1996
From:	Entergy Corp
To:	Office of Nuclear Reactor Regulation, NRC/OGC, NRC Region 1
References
CR-PNP-1996-00396
Download: ML070780367 (22)

Text

EnteLqgy CONDITION REPORT CR-PNP-1996-00396 Originator: CONVERTED DATA Originator Phone: 0 Originator Group: CONVERTED DATA Operability Required: N Reportability Required: N Supervisor Name: CONVERTED DATA Discovered Date: 09/24/1996 0O:OO Initiated Date: 09/24/1996 0O:OO Condition

Description:

HIGH MITRATE LEVELS EXIST IN THE TBCCW SYSTEM. HIGH NITRATE CONCENTRATIONS HAVE BEEN ASSOCIATED WITH STRESS CORROSION CRACKING OF CARBON STEEL PIPING.

Immediate Action

Description:

Suggested Action

Description:

EQUIPMENT:

Tag Name Tag Suffix Name Component Code Process Svstem Code 30B REFERENCE ITEMS:

Type Code DescriDtion CONVERTED PR PR.96.0396

Enfefgy ADMIN CR-PNP-1996-00396 Initiated Date: 9/24/1996 0:OO Owner Group :CA&A Staff Current

Contact:

MCDONALD, G.

Current Significance: D - ADMIN CLOSE Closed by: MCDONALD, G. 10/1/1996 0:OO Summary

Description:

HIGH MITRATE LEVELS EXIST IN THE TBCCW SYSTEM. HIGH NITRATE CONCENTRATIONSHAVE BEEN ASSOCIATED WITH STRESS CORROSION CRACKING OF CARBON STEEL PIPING.

Remarks

Description:

HIGH NITRATE TBCCW CHEMISTRY TRENDING DECREASING NITRITE INCREASING CONDUCTIVITY RBCCW STRESS CORROSION CRACKING BACTERIA CORROSION INHIBITOR SODIUM NITRITE EXCESS OXYGEN CARBON STEEL PIPING Closure

Description:

PAC REVIEW AFTER EVALUATION EVALUATION AND CORRECTIVE ACTION COMPLETE

Entergy ASSIGNMENTS CR-PNP-1996-00396 Version: 1 Significance Code: D - ADMIN CLOSE ClassificationCode: NON-SIGNIFICANT Owner Group: CA&A Staff Performed By: Shatas,Albert A 09/24/1996 0O:OO Assignment

Description:

SCREEN IAW NOP92A1 I

CORRECTIVE ACTION 1 CR-PNP-1996-00396 CA Number: 1 r-Grout, - - I - - Name f Assigned By: CA&A Staff SHATAS, A.

Assigned To: CA&A Staff Shatas,Albert A Subassigned To :

Originated By: SHATAS, A. 9/24/1996 0O:OO:OO Performed By: SHATAS, A. 9/24/1996 0O:OO:OO Subperformed By:

Approved By:

Closed By: SHATAS, A. 9/24/1996 0O:OO:OO Current Due Date: 10/01/1996 Initial Due Date: 10/01/1996 CAType: GENERAL Plant Constraint: NONE CA

Description:

SCREEN IAW NOP92A1

Response

CONVERTED DATA Subresponse :

Closure Comments:

PAC APPROVED NOP92A1 EXHIBIT 3

~~

I I CA Number: 2 I 1"

- I

_ - -I Group - - Name Assigned By: Tech Chemistry Staff LOOMIS, L.

Assigned To: Tech Chemistry Staff Loomis,Larry Subassigned To :

Originated By: LOOMIS, L. 9/24/1996 0O:OO:OO Performed By: LOOMIS, L. 7/ 14/1997 0O:OO:OO Subperformed By:

Approved By:

Closed By: LOOMIS, L. 7/14/1997 0O:OO:OO Current Due Date: 08/30/1997 Initial Due Date: 08/30/1997 CA Type: GENERAL Plant Constraint: NONE CA

Description:

CONDUCT AN EVALUATION TO DETERMINE THE CAUSE OF THE HIGH NITRATE LEVELS IN THE TBCCW SYSTEM. DETERMINE CORRECTIVE ACTIONS AND ACTIONS TO PRECLUDE RECURRENCE.

Response

COMPLETE EVALUATION PER NOP92A1, SECTION 6.4.

PROBLEM DESCRIPTION: HIGH NITRATE LEVELS EXIST IN THE TBCCW SYSTEM WHICH HAVE BEEN ASSOCIATED WITH SCC IN CARBON STEEL PIPING.

DIRECT CAUSE: ONE LIKELY CAUSE COULD HAVE BEEN A SYSTEM LEAK WHICH INTRODUCES AIR WHICH CONVERTS NITRITE (THE CHEMICAL ADDITIVE) TO NITRATEL. HOWEVER, THE TBCCW SYSTEM IS KNOWN TO BE A TIGHT SYSTEM WITH LITTLE LEAKAGE.

ANOTHER POSSIBLE CAUSE SEEN IN THE INDUSTRY IS THE CONVERSION OF NITRITE TO NITRATE DUE BACTERIA. THIS IS LIKELY CONSIDERING SYSTEM CONDITIONS SUCH AS TEMPERATURE AND FLOW.

REPEAT OCCURRENCE: NO MAINTENANCERULE: UNKNOWN Subresponse :

Closure Comments:

COMPLETE EVALUATION PER NOP92A1, SECTION 6.4.

PROBLEM DESCRIPTION: HIGH NITRATE LEVELS EXIST IN THE TBCCW SYSTEM WHICH HAVE BEEN ASSOCIATED WITH SCC IN CARBON STEEL PIPING.

DIRECT CAUSE: ONE LIKELY CAUSE COULD HAVE BEEN A SYSTEM LEAK WHICH INTRODUCES AIR WHICH CONVERTS NITRITE (THE CHEMICAL ADDITIVE) TO NITRATEL. HOWEVER, THE TBCCW SYSTEM IS KNOWN TO BE A TIGHT SYSTEM WITH LITTLE LEAKAGE.

ANOTHER POSSIBLE CAUSE SEEN IN THE INDUSTRY IS THE CONVERSION OF NITRITE TO NITRATE DUE BACTERIA. THIS IS LIKELY CONSIDERING SYSTEM CONDITIONS SUCH AS TEMPERATURE AND FLOW.

REPEAT OCCURRENCE: NO MAINTENANCE RULE: UNKNOWN

E n t m I CA DUE DATE EXTENSION I CR-PNP-1996-00396 C o r r e c t i v e Action :-CR-PNP-1996-00396 CA-00002 Version: 3 Approved:

Requested Duedate: 08/30/1997 Previous Duedate: 08/29/1997 Requested By: CONVERTED DATA 08/23/1997 Approved By: CONVERTED DATA 08/23/1991 Request

Description:

CONVERTED DATA Approved

Description:

CONVERTED DATA

E n f q CORRECTIVE ACTION CR-PNP-1996-00396 CA Number: 3 11 I

1--

Group Name Assigned By: Eng DE Mech Civil Struct Staff WHITE, T.F.

Assigned To: Eng DE Mech Civil Struct Staff Pace,Raymond M Subassigned To :

Originated By: WHITE, T.F. 9/24/1996 0O:OO:OO Performed By: PACE, R. 2/4/1997 0O:OO:OO jubperformed By:

Approved By:

Closed By: WHITE, T.F. 2/4/1997 0O:OO:OO Current Due Date: 01/15/1997 Initial Due Date: 01/15/1997 CA Type: GENERAL Plant Constraint: NONE CA

Description:

DETERMINE THE EFFECTS OF THE ELEVATED NITRATE LEVELS ON THE CARBON STEEL PIPJNG OF THE TBCCW SYSTEM.

Response

MEMO DETAILING THE RESULTS THE EVALUATION AND THE REQUIRED CORRECTIVE ACTIONS.

CONCURRENCE MUST BE OBTAINED FROM ACTION ITEM OWNERS.

NOTE: CHEMISTRY HAS ALSO BEEN ASSIGNED AN ACTION TO DETERMINE THE CAUSE OF THE EXCESS NITRATE AND SHOULD BE ABLE TO PROVIDE ADDITIONAL INFORMATION TO ASSIST IN YOUR EVALUATION.

PROBLEM REPORT PROBLEM REPORT No. 96.0396.02

1. Problem

Description:

High Nitrate levels exist in the TBCCW System. High Nitrate concentrations have been associated with stress corrosion cracking of carbon steel piping.

2. Apparent/Direct Cause:

Based on a study of literature on this subject, the likely direct cause is Nitrobacter bacteria conversion of Nitrites to Nitrates.

An action item should be given Chemistry to sample and analyze the RBCCW and TBCCW, including the make-up water source, for the presence of Nitrobacter bacteria.

3. Repeat Occurrence: u YES NO

4. Maintenance Rule Functional Failure: -YES -u- NO -Unknown

5. Corrective Actions Completed (include Dates if possible)

A literature search (See Attached Letter for details and date completed) was performed to determine the most probable cause of the Nitrate build-up and its affect on carbon steel piping. Based on this research for the Nitrate concentration, system operating conditions and the duration of the present problem, the probability of developing stress corrosion cracking is low.

However due to the lack of conclusive data at the appropriate operating conditions there is sufficient probability of stress corrosion cracking that an action item should be given to the MSTP Group to develop a program of sufficient duration to inspect TBCCW piping welds. Civ/ Struct./ Mech will assist the MSTP Group in the selection of inspection locations, as necessary.

6. Corrective Actions Required 13U (check "NR" if not required) -NIR a) Action Required chemistry to sample and analyze the RBCCW and TBCCW, including the make-up water source, for the presence of Nitrobacter bacteria.

OClosure Requirement If Nitrobacter bacteria are found a biocide should be introduced as a part of a chemical treatment program to eliminate the bacteria and reduce the Nitrate concentration.

Responsible Manager Dave Fountain Due Date 04/01/97 E 0ODead Date 05/30/97 b) Action Required MSTP Group develop a weld inspection program.

EClosure Requirement MSTP Group develop a weld inspection program of sufficient duration for TBCCW piping welds.

Responsible Manager Kevin Burke

--- ~

~

Entwgy CORRECTIVE ACTION CR-PNP-1996-00396

7. Corrective Actions Required to Preclude Recurrence (check "NR"if not required) __ N/R a) Action Required Mechanical select inspection points.

Closure Requirement Mechanical/Civil/Structural selection of 5 to 10 inspection points based on the attached letter with proposed Altran criteria.

Responsible Manager Thomas White, Jr.

Due Date 04/01/97 ODead Date 05/31/97 b) Action Required Closure Requirement Responsible Manager Due Date / / 00 ODead Date -/-/-

8. Trend Data for Apparent Cause@0 (check "N/R" for Direct Cause Analysis) u N/R NOTE If more than 2 Inappropriate Actions are defined, use Exhibit 14.

a) Inappropriate Action (IA)

Description:

IA Job Title IA Group IA Department IA Job Title IA Group IA Department BECO OContractor Work Process Key Activity Work Process Key Activity O&P Failure Mechanism HEIA Failure Mechanism Human Error Type (Circle 1): Skill BasedU Subresponse :

EntHgy CORRECTIVE ACTION CR-PNP-1996-00396 Closure Comments:

MEMO DETAILING THE RESULTS THE EVALUATION AND THE REQUIRED CORRECTIVE ACTIONS.

CONCURRENCE MUST BE OBTAINED FROM ACTION ITEM OWNERS.

NOTE: CHEMISTRY HAS ALSO BEEN ASSIGNED AN ACTION TO DETERMINE THE CAUSE OF THE EXCESS NITRATE AND SHOULD BE ABLE TO PROVIDE ADDITIONAL INFORMATION TO ASSIST IN YOUR EVALUATION.

PROBLEM REPORT PROBLEM REPORT No. 96.0396.02 1 . Problem

Description:

High Nitrate levels exist in the TBCCW System. High Nitrate concentrations have been associated with stress corrosion cracking of carbon steel piping.

2. Apparent/Direct Cause:

Based on a study of literature on this subject, the likely direct cause is Nitrobacter bacteria conversion of Nitrites to Nitrates.

An action item should be given Chemistry to sample and analyze the RBCCW and TBCCW, including the make-up water source, for the presence of Nitrobacter bacteria.

3. Repeat Occurrence: u YES NO 4.Maintenance Rule Functional Failure: -YES -u- NO -Unknown

5. Corrective Actions Completed (include Dates if possible)

A literature search (See Attached Letter for details and date completed) was performed to determine the most probable cause of the Nitrate build-up and its affect on carbon steel piping. Based on this research for the Nitrate concentration, system operating conditions and the duration of the present problem, the probability of developing stress corrosion cracking is low.

However due to the lack of conclusive data at the appropriate operating conditions there is sufficient probability of stress corrosion cracking that an action item should be given to the MSTP Group to develop a program of sufficient duration to inspect TBCCW piping welds. Civ/ Struct./ Mech will assist the MSTP Group in the selection of inspection locations, as necessary.

6. Corrective Actions Required 00 (check "NIR" if not required) -NIR a) Action Required Chemistry to sample and analyze the RBCCW and TBCCW, including the make-up water source, for the presence of Nitrobacter bacteria.

CClosure Requirement If Nitrobacter bacteria are found a biocide should be introduced as a part of a chemical treatment program to eliminate the bacteria and reduce the Nitrate concentration.

Responsible Manager Dave Fountain Due Date 04/01/970 0ODead Date 05/30/97 b) Action Required MSTP Group develop a weld inspection program.

OClosure Requirement MSTP Group develop a weld inspection program of sufficient duration for TBCCW piping welds.

Responsible Manager Kevin Burke

Ent43g-y CORRECTIVE ACTION CR-PNP-1996-00396

7. Corrective Actions Required to Preclude Recurrence (check "NR"if not required) __ N/R a) Action Required Mechanical select inspection points.

Closure Requirement Mechanical/CiviYStructural selection of 5 to 10 inspection points based on the attached letter with proposed Altran criteria.

Responsible Manager Thomas White, Jr.

Due Date 04/01/970ODead Date 05/31/97 b) Action Required Closure Requirement Responsible Manager DueDate / / UDODeadDate / /

8. Trend Data for Apparent Cause0 0 (check "NR"for Direct Cause Analysis) u N/R NOTE If more than 2 Inappropriate Actions are defined, use Exhibit 14.

a) Inappropriate Action (IA)

Description:

IA Job Title IA Group IA Department IA Job Title IA Group IA Department BECO UContractor Work Process Key Activity Work Process Key Activity O&P Failure Mechanism HEIA Failure Mechanism Human Error Type (Circle 1): Skill BasedU

4 I I EmfeGzY I CA DUE DATE EXTENSION CR-PNP-1996-00396 Version: 1 Approved:

Requested Duedate: 0 1/15/1997 Previous Duedate: 01/14/1997 Requested By: CONVERTED DATA 01/08/ 1997 Approved By: CONVERTED DATA 01/08/1997 Request

Description:

CONVERTED DATA Approved

Description:

CONVERTED DATA

Entergy CORRECTIVE ACTION CR-PNP-1996-00396 CA Number: 4 I

1111 I

I Name Assigned By: Tech Chemistry Staff SMALLEY, P.

Assigned To: Training Technical Staff Fountain,David W Subassigned To :

Originated By: SMALLEY, P. 2/6/1997 0O:OO:OO Performed By: FOUNTAIN, D. 4/3/1998 0O:OO:OO Subperformed By:

Approved By:

Closed By: SMALLEY, P. 4/3/1998 0O:OO:OO Current Due Date: 04/01/1998 Initial Due Date: 04/01/1998 CA Type: GENERAL Plant Constraint: NONE CA

Description:

CHEMISTRY TO SAMPLE AND ANALYZE THE RBCCW AND TBCCW, INCUDING THE MAKE-UP WATER SOURCE, FOR THE PRESENCE OF NITROBACTER BACTERIA.

Response

IF NITROBACTER BACTERIA ARE FOUND A BIOCIDE SHOULD BE INTRODUCED AS A PART OF A CHEMICAL TREATMENT PROGRAM TO ELIMINATE THE BACTERIA AND REDUCE THE NITRATE CONCENTRATION.

PROVIDE MEMO DOCUMENTING DETAILS OF TASK COMPLETION.

[4/2/98;FOUNTAIN, D.] TESTING WAS PERFORMED IN HOUSE DUE TO THE INABILITY TO LOCATE A QUALIFIED LABORATORY CAPABLE OF PERFORMING TESTING IN THIS AREA. (SAMPLES MUST BE AT THE VENDORS LABORATORY LESS THAN 24 HOURS AFTER SAMPLING.)

THE HACH COMPANY PROVIDES TEST KITS FOR PERFORMING NITROBACTERIATESTING ON SITE. THESE TEST KITS WERE PURCHASED AND SAMPLES WERE ANALYZED IN HOUSE FOR THE RBCCW, TBCCW AND MAKEUP WATER SYSTEMS. NO DETECTABLE NITROBACTERIAWAS IDENTIFIED.

MULTIPLE SAMPLES WERE ANALYZED ON THE TBCCW SYSTEM FROM VARIOUS LOCATIONS WHERE THE HIGHEST POTENTIAL FOR BACTERIA EXISTED. SAMPLES FROM THE SLIPSTREAM FTLTER WERE INCUBATED TO INCREASE THE NUMBER OF COLONIES PRESENT IF ANY NITROBACTERIAEXISTED.

THESE SAMPLES ALSO SHOWED NO SIGNS OF DETECTABLE NITROBACTERIA WHEN TESTED WITH THE HACH TEST KITS.

ADDITIONALLY, SAMPLES WERE TAKEN FOR TOTAL BACTERIA ON THESE SYSTEMS AND ZERO COLONIES WERE DETECTED. MONTHLY SAMPLING FOR TOTAL BACTERIA IS NOW ROUTINELY PERFORMED ON ALL CLOSED COOLING WATER SYSTEMS.

SAMPLINGFOR NITRATE LEVELS IN THE TBCCW SYSTEM (AND RBCCW) ARE ALSO PERFORMED MONTHLY. NO SIGNIFICANT TRENDS IN NITRATE HAVE BEEN IDENTIFIED.

THE RATIO OF THE 'SYSTEM CONDUCTIVITY' TO 'NITRITE IS ALSO CALCULATED DURING WEEKLY ANALYSIS. THIS IS ANOTHER METHOD TO DETERMINE IF ANY ADVERSE TRENDS ARE OCCURING WITHIN A CLOSED COOLING SYSTEM.

AGAIN NO SIGNIFICANT TRENDS HAVE BEEN IDENTIFIED.

DUE TO THE LACK OF TOTAL BACTERIA AND NITROBACTERIA AS DETERMINED BY GRAB SAMPLING THIS ITEM IS CLOSED. NO ADDITIONAL ACTIONS ARE REQUIRED UNLESS FUTURE ROUTINE TESTING WERE TO REVEAL ADVERSE TRENDS. A NEW PROBLEM REPORT WOULD BE GENERATED AT THAT TIME.

Entergy CORRECTIVE ACTION CR-PNP-1996-00396 Closure Comments:

IF NITROBACTER BACTERIA ARE FOUND A BIOCIDE SHOULD BE INTRODUCED AS A PART OF A CHEMICAL TREATMENT PROGRAM TO ELIMINATE THE BACTERIA AND REDUCE THE NITRATE CONCENTRATION.

PROVIDE MEMO DOCUMENTING DETAILS OF TASK COMPLETION.

[4/2/98;FOUNTAIN, D.] TESTING WAS PERFORMED IN HOUSE DUE TO THE INABILITY TO LOCATE A QUALIFIED LABORATORY CAPABLE OF PERFORMING TESTING J N THIS AREA. (SAMPLES MUST BE AT THE VENDORS LABORATORY LESS THAN 24 HOURS AFTER SAMPLING.)

THE HACH COMPANY PROVIDES TEST KITS FOR PERFORMING NITROBACTERIATESTING ON SITE. THESE TEST KITS WERE PURCHASED AND SAMPLES WERE ANALYZED IN HOUSE FOR THE RBCCW, TBCCW AND MAKEUP WATER SYSTEMS. NO DETECTABLE NITROBACTERIAWAS IDENTIFIED.

MULTIPLE SAMPLES WERE ANALYZED ON THE TBCCW SYSTEM FROM VARIOUS LOCATIONS WHERE THE HIGHEST POTENTIAL FOR BACTERIA EXISTED. SAMPLES FROM THE SLIPSTREAM FILTER WERE INCUBATED TO INCREASE THE NUMBER OF COLONIES PRESENT IF ANY NITROBACTERIAEXISTED.

THESE SAMPLES ALSO SHOWED NO SIGNS OF DETECTABLE NITROBACTERIAWHEN TESTED WITH THE HACH TEST KITS.

ADDITIONALLY, SAMPLES WERE TAKEN FOR TOTAL BACTERIA ON THESE SYSTEMS AND ZERO COLONIES WERE DETECTED. MONTHLY SAMPLING FOR TOTAL BACTERIA IS NOW ROUTINELY PERFORMED ON ALL CLOSED COOLING WATER SYSTEMS.

SAMPLING FOR NITRATE LEVELS IN THE TBCCW SYSTEM (AND RBCCW) ARE ALSO PERFORMED MONTHLY. NO SIGNIFICANT TRENDS IN NITRATE HAVE BEEN IDENTIFIED.

THE RATIO OF THE 'SYSTEM CONDUCTIVITY' TO 'NITRITE' IS ALSO CALCULATED DURING WEEKLY ANALYSIS. THIS IS ANOTHER METHOD TO DETERMINE IF ANY ADVERSE TRENDS ARE OCCURING WITHIN A CLOSED COOLING SYSTEM.

AGAIN NO SIGNIFICANT TRENDS HAVE BEEN IDENTIFIED.

DUE TO THE LACK OF TOTAL BACTERIA AND NITROBACTERIA AS DETERMINED BY GRAB SAMPLING THIS ITEM IS CLOSED. NO ADDITIONAL ACTIONS ARE REQUIRED UNLESS FUTURE ROUTINE TESTING WERE TO REVEAL ADVERSE TRENDS. A NEW PROBLEM REPORT WOULD BE GENERATED AT THAT TIME.

Entei?gy I CA DUE DATE EXTENSION CR-PNP-1996-00396 Version: 3 Approved:

Requested Duedate: 04/01/1998 Previous Duedate: 0313 111998 Requested By: CONVERTED DATA 03/25/1998 Approved By: CONVERTED DATA 03/25/1998 Request

Description:

CONVERTED DATA Approved

Description:

CONVERTED DATA

Ent43g-y CORRECTIVE ACTION CR-PI"-1996-00396 CA Number: 5 I __-I __

_I_-____ --- -----

i

- ---1-1 1--1-11111~1 I Group Name Assigned By: CA&A Staff WOLLMAN, S.

Assigned To: Operations Support Staff Burke,Kevin R Subassigned To :

Originated By: WOLLMAN, S. 2/6/1997 0O:OO:OO Performed By: BURKE, K. 5/22/1997 0O:OO:OO Subperformed By:

Approved By:

Closed By: WOLLMAN, S. 5/22/ 1997 00:00:00 Current Due Date: 05/30/1997 Initial Due Date: 05/30/1997 CA Type: GENERAL Plant Constraint: NONE CA

Description:

MSTP GROUP DEVELOP A WELD INSPECTION PROGRAM.

Entergy CORRECTIVE ACTION CR-PNP-1996-00396

Response

PROBLEM REPORT PROBLEM REPORT No. PR96.0396.05 1.UProblem

Description:

High nitrate levels exist in the TBCCW system. High nitrate concentrations have been associated with stress corrosion cracking of carbon steel piping.

2. O Apparent/ Direct Cause:

Based on a study of literature on this subject, the likely direct cause is Nitrobacter bacteria conversion of Nitrites to Nitrates.

3.ORepeat Occurrence: - -YES -X NO 4.OMaintenance Rule Functional Failure: -YES X - NO Unknown

5. OCorrective Actions Completed (include Dates if possible)

A past action item (PR.0396.02) was given Chemistry to sample and analyze the RBCCW and TBCCW, including the make-up water source, for the presence of Nitrobacter bacteria.

Mechanical/ Civil/ Structural selection of 5 to 10 inspection points based on the Altran Letter with proposed criteria.

6. @CorrectiveActions Required 000 (check "NtR" if not required) - - NtR a) Action Required Visual inspection program developed for selected points. See Attached.

Closure Requirement Visual inspection program implemented. See Attached.

Responsible Manager C. Garrow Due Date: 06 / 30t 97 00ODead Date: 08 t 3 1 / 97

7. CCorrective Actions Required to Preclude Recurrence (check "N/R" if not required) 4 N/R 08.ClTrend Data for Apparent CauseOU (check " N W for Direct Cause Analysis) -X-N/R

9. OThe Significance should: Be Upgraded 4 Remain the Same If applicable, the reason for the upgraded:NtA Completed By: R. PACE Date: 4 t 8 1 00 EvaluatortMentor Approved By: T. WHITE Date: 4 I 8 t 0 Manager PROBLEM STATEMENT As discussed in PR 96.0396.02 [3] it has been determined that elevated nitrate concentrations can result in intergranular stress corrosion cracking (IGSCC) of carbon steel (CS) piping. Because Pilgrim Nuclear Power Station (PNPS) has had a short duration of marginally unacceptable nitrate concentrations, PR 96.0396.05 requests that NESG, Mechanical/ Civil/ Structural select 5 to 10 inspection locations on the affected Turbine Building Closed Cooling Water (TBCCW) system [4].

SUMMARY

Eleven inspection locations have been selected for the inservice inspection (ISI) of the TBCCW piping for IGSCC. It is recommended that an inspection program be implemented that is 10 years in duration with 2 year inspection intervals. The n

Entqgy CORRECTIVE-2??5~i ON CR-PNP-1996-00396 Iocations should be selected or each inspection interval and results reported to NESG (Mechanical/ Civil/ Structural). All locations should be visually inspected at a minimum of two inspection intervals over the program duration.

If problems are discovered during later inspections the scope would be expanded by the addition of several new locations for inspection and the use of volumetric inspection techniques. In this case, criteria for scope expansion will be developed based on the inspection results and water chemistry history. Therefore nitrate concentration history is an important input to the program. Chemistry was given an action item [3] to develop a program and document this information to NESG. If no IGSCC is found over the recommended program duration and low nitrate levels ( 4 0 0 PPM) are maintained the inspection program can be discontinued.

A closed cooling water/ plant heating corrosion monitoring system will be installed in the near future. If a corrosion sample for the TBCCW system containing a carbon steel weld (Pl) can be incorporated into the program the piping inspections may be eliminated. The monitoring of the corrosion sample is a more accurate predictor of the system condition.

ASSUMPTIONS As stated in the Altran Corporation letter attached to the problem report, IGSCC is not co Subresponse :

Closure Comments:

MSTP GROUP DEVELOP A W L D INSPECTION PROGRAM OF SUFFICIENT DURATION FOR TBCCW PIPING WELDS. PROVIDE MEMO DOCUMENTING DETAILS OF TASK COMPLETION.

CLOSURE: MSTP NODE SO01262 CREATED TO TRACK WELD SELECTION AND EXAMINATION.

Entegy CORRECTIVE ACTION CR-PNP-1996-00396 CA Number: 6 r-t I_ _I-I Group Name Assigned By: Eng DE Mech Civil Struct Staff WHITE, T.F.

Assigned To: Eng DE Mech Civil Struct Staff Pace,Raymond M Subassigned To :

Originated By: WHITE, T.F. 2/6/1997 0O:OO:OO Performed By: PACE, R. 5/7/1997 0O:OO:OO subperformed By:

Approved By:

Closed By: WHITE, T.F. 5/7/1997 0O:OO:OO Current Due Date: 05/31/1997 Initial Due Date: 05/31/1997 CA Type: GENERAL Plant Constraint: NONE CA

Description:

MECHANICAL SEAL INSPECTION POINTS.

Response

CONVERTED DATA Subresponse :

CORRECTIVE ACTION I CR-PNP-1996-00396 Closure Comments:

MECHANICAL/CIVIL/STRUCTURAL SELECTION OF 5 TO 10 INSPECTION POINTS BASED ON THE ATTACHED LETTER WITH PROPOSED ALTRAN CRITERIA PROBLEM REPORT PROBLEM REPORT No. PR96.0396.05 1.@ProblemDescription:

High nitrate levels exist in the TBCCW system. High nitrate concentrations have been associated with stress corrosion cracking of carbon steel piping.

2.0 Apparent/ Direct Cause:

Based on a study of literature on this subject, the likely direct cause is Nitrobacter bacteria conversion of Nitrites to Nitrates.

3.0Repeat Occurrence: - -YES X NO 4.OMaintenance Rule Functional Failure: -YES -X- NO Unknown 5.OCorrective Actions Completed (include Dates if possible)

A past action item (PR.0396.02) was given Chemistry to sample and analyze the RBCCW and TBCCW, including the make-up water source, for the presence of Nitrobacter bacteria.

Mechanical1 Civil/ Structural selection of 5 to 10 inspection points based on the Altran Letter with proposed criteria.

6.CiCorrective Actions Required 000 (check "NR" if not required) - - N/R a) Action Required Visual inspection program developed for selected points. See Attached.

Closure Requirement Visual inspection program implemented. See Attached.

Responsible Manager C. Garrow Due Date: 06 I 30/ 97 00ODead Date: 08 / 3 1 / 97 7.OCorrective Actions Required to Preclude Recurrence (check "N/R" if not required) 4 N/R

08. OTrend Data for Apparent Cause0 0 (check "N/R" for Direct Cause Analysis) X N/R

9. OThe Significance should: Be Upgraded 4 Remain the Same If applicable, the reason for the upgraded:N/A Completed By: R. PACE Date: 4 I 8 1 on EvaluatorIMentor Approved By: T. WHITE Date: 4 I 8 1 00Manager PROBLEM STATEMENT As discussed in PR 96.0396.02 [3] it has been determined that elevated nitrate concentrations can result in intergranular stress corrosion cracking (IGSCC) of carbon steel (CS) piping. Because Pilgrim Nuclear Power Station (PNPS) has had a short duration of marginally unacceptable ritrate concentrations, PR 96.0396.05 requests that NESG, Mechanical/ CiviY Structural select 5 to 10 inspection locations on the affected Turbine Building Closed Cooling Water (TBCCW) system [4].

I Entergy I CORRECTIVE ACTION CR-PNP-1996-00396 If problems are discovered during later inspections the scope would be expanded by the addition of several new locations for inspection and the use of volumetric inspection techniques. In this case, criteria for scope expansion will be developed based on the inspection results and water chemistry history. Therefore nitrate concentration history is an important input to the program. Chemistry was given an action item [3] to develop a program and document this information to NESG. If no IGSCC is found over the recommended program duration and low nitrate levels (400PPM) are maintained the inspection program can be discontinued.

A closed cooling water/ plant heating corrosion monitoring system will be installed in the near future. If a corrosion sample for the

I CR-PNP-1996-00396 I I I CORRECTIVE ACTION CA Number:

- l _ l - _

7

- .-. _lll_

Group

.___-___I._ --

I

- I 1 ~

Name

- -I-1l-x-_.-l ~.

Assigned By: QA Staff SHERIDAN, R.

Assigned To: QA Staff Garrow,Charles G Subassigned To :

Originated By: SHERIDAN, R. 5/14/1997 0O:OO:OO Performed By: GARROW, C. 5/19/1997 0O:OO:OO Subperformed By:

Approved By:

Closed By: SHERIDAN, R. 5/19/1997 0O:OO:OO I

~ Current Due Date: 08/31/1997 Initial Due Date: 08/31/1997 CA Type: GENERAL Plant Constraint: NONE CA

Description:

VISUAL INSPECTION PROGRAM DEVELOPED FOR SELECTED POINTS.

Response

CONVERTED DATA Subresponse :

Closure Comments:

VISUAL INSPECTION PROGRAM IMPLEMENTED.

CLOSURE: THE EXAMINATIONREQUIREMENTS WILL BE TRACKED BY THE MSTP TRACKING PROGRAM (ATTACHEDFORM) WITH EXAMINATION PERFORMED TO EXISTING PROCEDURES. THE INSPECTIONS WILL BE IMPLEMENTED WITH AN MR AS WITH ALL OTHER IS1 EXAMINATIONS. NODE #S001262.