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Category:INTERNAL OR EXTERNAL MEMORANDUM
MONTHYEARML20217A9811999-10-30030 October 1999 Forwards Sept 1999 Performance Indicator Data Rept for Revised Reactor Oversight Process Pilot Program.Rept Includes Data Through Aug 1999 (two-thirds of 3rd Quarter of 1999) for 13 Units at 9 Pilot Sites ML20211H4441999-08-27027 August 1999 Notification of Significant Meeting with Util on 990916 & 17 in Arlington,Tx to Improve Utility & NRC Understanding of Industry & Regulatory Perspectives on Current Issues ML20210J9721999-08-0202 August 1999 Notification of 990817 Meeting with Util in Rockville,Md to Discuss Util Radiological Consequences Improvement Program Implementation,Program Impact on Util Response to GL 99-02 & Alternate Course of Action to Requirements Discussed in GL ML20210F6981999-07-27027 July 1999 Discusses 990430 Request for Waiver of 10CFR170 Fees for Certain Insp Efforts Re NRR Pilot Regulatory Oversight Program.Determined That Thirteen Plants in Pilot Program Will Be Exempted from 10CFR170 Fees for Insp Efforts ML20196J5661999-07-0101 July 1999 Notification of 990714 Meeting with OPPD & CE in Rockville, Maryland to Discuss Staff Concerns with OPPD PTLR Submittal & CEOG Topical Rept CE NPSD-683 ML20196H8491999-06-28028 June 1999 Forwards June 1999 Performance Indicator (PI) Data Rept for Revised Reactor Oversight Process Pilot Program.Rept Constitutes Second Monthly PI Data Submittal from Pilot Plant Licensees,Which Includes Data Through May 1999 ML20207G4241999-06-0202 June 1999 Notification of 990630 Meeting with Util in Fort Calhoun, Nebraska to Discuss Miscellaneous Management Topics & Plant Status ML20207D3251999-05-28028 May 1999 Notification of 990617 Meeting with Util in Blair,Nebraska to Inform Public of NRC Plans for Implementing Risk Informed Baseline Insp Pilot Program at Fort Calhoun Station ML20210F7021999-04-30030 April 1999 Requests Waiver of Fees for Thirteen Dockets That Compromise Plant Population for NRR Pilot Regulatory Oversight Program. Purposes of Pilot Program Described in Commission Papers SECY-99-007 & SECY-99-007A ML20205N1741999-04-12012 April 1999 Notification of Revised Licensee Meeting with Util on 990419 to Discuss Results of PPR Completed 990211.New Location of Meeting Will Be in Visiting Inspector room,2nd Floor at Fort Calhoun Station,Admin Bldg,Fort Calhoun,Ne ML20204J0221999-03-19019 March 1999 Notification of 990419 Meeting with Omaha Public Power District to Discuss Results of Plant Performance Review Completed on 990211 ML20207L7181999-03-0202 March 1999 Notification of 990318 Meeting with OPPD in Rockville, Maryland to Discuss OPPD NPSH Calculation Used to Support Fort Calhoun Station USAR Change to Take Credit for Containment Overpressure or Sump Subcooling ML20198M3071998-12-31031 December 1998 Notification of 990114 Meeting with Util in Rockville,Md to Discuss Fort Calhoun Station Radiological Consequences Improvement Program Issues & Implementation ML20196D3341998-11-24024 November 1998 Notification of 981204 Meeting with Util in Rockville,Md to Discuss Fort Calhoun Station Radiological Consequences Improvement Program Issues & Implementation ML20195B4071998-11-0404 November 1998 Notification of 981130 Licensee Meeting with Util in Arlington,Tx to Discuss Recent License Exam Results ML20154L3781998-10-15015 October 1998 Notification of 981020 Meeting W/Util to Discuss Regional Administrator OPPD Common Cause Analysis ML20154C2211998-10-0101 October 1998 Notification of Licensee Meeting with Util on 981015 in Arlington,Tx to Discuss Maint & Engineering Issues Related to turbine-driven & diesel-driven Auxiliary Feedwater Pumps Overspeed Events ML20153D7441998-09-21021 September 1998 Notification of 981006 Meeting with Util in Fort Calhoun,Ne to Discuss Common Cause Analysis ML20236X5111998-08-0606 August 1998 Notification of 980819 Meeting W/Omaha Public Power District in Rockville,Md to Discuss Fort Calhoun Station Refueling Outage Accomplishments,Challenges & Emerging Issues ML20236M9621998-07-0808 July 1998 Notification of 980723 Meeting W/Util in Arlington,Tx to Discuss Licensee Performance ML20249C6141998-06-22022 June 1998 Revised Notification of Licensee Meeting W/Util on 980710 to Discuss Switchyard Mods at Fort Calhoun Station ML20248L2961998-06-0505 June 1998 Notification of Significant Licensee Meeting W/Util on 980710 to Discuss Switchyard Mods at Fort Calhoun Station ML20247M1631998-05-14014 May 1998 Refers to GL 92-01,Rev 1,Supplement 1, Rv Structural Integrity, Issued in May 1995.RAI Re Plant 971013 Submittal of Revised Rv Weld Chemistry Valves Encl.Response Requested within 90 Days of Receipt of Ltr ML20217K3251998-04-28028 April 1998 Notification of 980505 Meeting W/Nebraska Public Power District in Arlington,Tx to Discuss Current Operations Dept Issues ML20203F7461998-02-23023 February 1998 Notification of 980309 Meeting W/Util in Arlington,Tx to Discuss Switchyard Mods at FCS ML20198E2091997-12-30030 December 1997 Requests Attached 4 Pages Be Placed in Docket File & Pdr. Suppl to 961120 Application to Amend Fort Calhoun License & Tss.Document Faxed Concurrence of License Commitment Re Relocation of Certain TS Requirements ML20199H2531997-11-24024 November 1997 Forwards Signed Original of Order Prohibiting Involvement in NRC-licensed Activities (Effective Immediately) Fs Bandy,For Transmittal to Ofc of Fr for Publication.W/O Encl ML20198Q2461997-10-31031 October 1997 Notification of 971113 Meeting W/Util in Rockville,Md to Discuss Issues Related to FCS Fire Protection Improvements, USAR Verification & OPPD Proposal for Submitting Substantial TS Changes in Lieu of Coverting to Std TS ML20217B4311997-09-22022 September 1997 Notification of 971007 Predecisional Enforcement Conference W/Util in Arlington,Tx to Discuss Disabling of Containment Spray Sys ML20210N8801997-08-21021 August 1997 Notification of Licensee Meeting W/Util on 970924 in Blair, Ne to Discuss Systematic Assessment of Licensee Performance. Meeting Open to Attendance by Members of General Public ML20217M0521997-08-14014 August 1997 Informs That Operator Licensing Exams Administered on 970414-0506 at Fort Calhoun,Unit 1.Listed Info for Processing Through Nudocs & Distribution to NRC Staff Including NRC PDR Also Encl ML20210J0951997-08-0505 August 1997 Informs That NRC Plans to Administer Gfes of Written Operator Licensing Exam at Facility on 971008.Requests That Listing of Names of Candidates for Exam Be Submitted to Listed Individuals by 970908 ML20141G9081997-07-0707 July 1997 Notification of 970721 Predecisional Enforcement Conference in Arlington,Texas to Discuss Apparent Violation of 10CFR50.65 Related to 970421 Steamline Rupture Event ML20138E3261997-04-29029 April 1997 Notification of Significant Licensee Meeting W/Util on 970505 to Discuss Steam Line Break,Root Cause Analysis & Corrective Actions ML20134P2231997-02-20020 February 1997 Discusses Ti 2515/122 Evaluation or Rosemount Pressure Transmitter Performance & Licensee Enhanced Surveillance Programs multi-plant Action B-122 ML20133H7781997-01-14014 January 1997 Notification of Significant Licensee Meeting W/Util on 970129 in Arlington,Tx to Discuss Issues Re Post-Accident Sample Sys ML20129E7041995-12-29029 December 1995 Forwards NRC Approved Operator Licensing Exam (Facility Outline & Initial Exam Submittal) for Tests Administered on 951204-08 ML20136A7871995-12-19019 December 1995 Partially Withheld Memo Discussing Petition Filed by Jf Doherty Requesting Six Plant Reactors Be Immediately Shutdown & Directors Decision 95-22 Which Denies Request NUREG-1299, Forwards Continuation of Curtiss Papers to Be Filed Under Commission Correspondence in Pdr.Advanced Copy Sent to Pdr. List of Documents Included in Four Boxes Encl1994-06-29029 June 1994 Forwards Continuation of Curtiss Papers to Be Filed Under Commission Correspondence in Pdr.Advanced Copy Sent to Pdr. List of Documents Included in Four Boxes Encl ML20059H8831994-01-24024 January 1994 Submits Daily Highlight Re 940127 Meeting W/Util in Rockville,Md to Discuss Plant Plans for Future Amends & Current Licensing Status ML20058K1231993-12-0202 December 1993 Forwards CS Wingo of FEMA Transmitting Final Exercise Rept for 930629 Exercise of Offsite Radiological Emergency Response Plans for Plant.Eight Deficiencies Noted During Exercise ML20057B3401993-09-13013 September 1993 Requests That NRR Provide Review of Concern Re Licensee TS Action Statement for Inoperable Channel for SIRWT Level to Determine If It Is Appropriate to Request Change Be Initiated to Plant TS ML20127E5081993-01-13013 January 1993 Notification of 930203 Meeting W/Util in Rockville,Md to Discuss Significant Plant Issues Such as Pts,Pra & Power Uprate & Current Status ML20126M2671992-12-24024 December 1992 Notification of Canceled 930107 Meeting in Rockville,Md Re Pressurized Thermal Shock,Probabalistic Risk Assessment & Plans for Future Power Uprate & Current Status.Proposed Agenda Encl ML20125B8211992-12-0404 December 1992 Notification of 921204 Meeting W/Util in Rockville,Md to Discuss Significant Plant Issues,Including Pts,Pra & Plan for Future Power Uprate & Current Status.Date Changed ML20128D1651992-11-24024 November 1992 Notification of 921209 Meeting W/Util in Rockville,Md to Discuss Significant Issues Such as Pts,Pra & Plans for Future Power Uprate & Current Status ML20055G4901990-07-16016 July 1990 Notification of 900726 Mgt Meeting W/Util in Omaha,Ne to Discuss SALP Rept 50-285/90-24 for May 1989 - Apr 1990 ML20198C4071990-06-22022 June 1990 Requests That NRR Review Basis of TS 2.16 to Determine If Basis Represents Nonconservative Approach to Safe Plant Operation ML20055C8721990-06-21021 June 1990 Notification of Significant Licensee Meeting W/Util on 900724 to Discuss Changes in Rev 6 of Examiner Stds & Exam Schedule for 1991 ML20248E8841989-10-0202 October 1989 Notification of 891005 Meeting W/Util in Region IV Ofc to Present Results of Licensee Evaluation of Delta T/Nuclear Power Deviation Anomaly 1999-08-27
[Table view] Category:MEMORANDUMS-CORRESPONDENCE
MONTHYEARML20217A9811999-10-30030 October 1999 Forwards Sept 1999 Performance Indicator Data Rept for Revised Reactor Oversight Process Pilot Program.Rept Includes Data Through Aug 1999 (two-thirds of 3rd Quarter of 1999) for 13 Units at 9 Pilot Sites ML20211H4441999-08-27027 August 1999 Notification of Significant Meeting with Util on 990916 & 17 in Arlington,Tx to Improve Utility & NRC Understanding of Industry & Regulatory Perspectives on Current Issues ML20210J9721999-08-0202 August 1999 Notification of 990817 Meeting with Util in Rockville,Md to Discuss Util Radiological Consequences Improvement Program Implementation,Program Impact on Util Response to GL 99-02 & Alternate Course of Action to Requirements Discussed in GL ML20210F6981999-07-27027 July 1999 Discusses 990430 Request for Waiver of 10CFR170 Fees for Certain Insp Efforts Re NRR Pilot Regulatory Oversight Program.Determined That Thirteen Plants in Pilot Program Will Be Exempted from 10CFR170 Fees for Insp Efforts ML20196J5661999-07-0101 July 1999 Notification of 990714 Meeting with OPPD & CE in Rockville, Maryland to Discuss Staff Concerns with OPPD PTLR Submittal & CEOG Topical Rept CE NPSD-683 ML20196H8491999-06-28028 June 1999 Forwards June 1999 Performance Indicator (PI) Data Rept for Revised Reactor Oversight Process Pilot Program.Rept Constitutes Second Monthly PI Data Submittal from Pilot Plant Licensees,Which Includes Data Through May 1999 ML20207G4241999-06-0202 June 1999 Notification of 990630 Meeting with Util in Fort Calhoun, Nebraska to Discuss Miscellaneous Management Topics & Plant Status ML20207D3251999-05-28028 May 1999 Notification of 990617 Meeting with Util in Blair,Nebraska to Inform Public of NRC Plans for Implementing Risk Informed Baseline Insp Pilot Program at Fort Calhoun Station ML20210F7021999-04-30030 April 1999 Requests Waiver of Fees for Thirteen Dockets That Compromise Plant Population for NRR Pilot Regulatory Oversight Program. Purposes of Pilot Program Described in Commission Papers SECY-99-007 & SECY-99-007A ML20205N1741999-04-12012 April 1999 Notification of Revised Licensee Meeting with Util on 990419 to Discuss Results of PPR Completed 990211.New Location of Meeting Will Be in Visiting Inspector room,2nd Floor at Fort Calhoun Station,Admin Bldg,Fort Calhoun,Ne ML20204J0221999-03-19019 March 1999 Notification of 990419 Meeting with Omaha Public Power District to Discuss Results of Plant Performance Review Completed on 990211 ML20207L7181999-03-0202 March 1999 Notification of 990318 Meeting with OPPD in Rockville, Maryland to Discuss OPPD NPSH Calculation Used to Support Fort Calhoun Station USAR Change to Take Credit for Containment Overpressure or Sump Subcooling ML20198M3071998-12-31031 December 1998 Notification of 990114 Meeting with Util in Rockville,Md to Discuss Fort Calhoun Station Radiological Consequences Improvement Program Issues & Implementation ML20196D3341998-11-24024 November 1998 Notification of 981204 Meeting with Util in Rockville,Md to Discuss Fort Calhoun Station Radiological Consequences Improvement Program Issues & Implementation ML20195B4071998-11-0404 November 1998 Notification of 981130 Licensee Meeting with Util in Arlington,Tx to Discuss Recent License Exam Results ML20154L3781998-10-15015 October 1998 Notification of 981020 Meeting W/Util to Discuss Regional Administrator OPPD Common Cause Analysis ML20154C2211998-10-0101 October 1998 Notification of Licensee Meeting with Util on 981015 in Arlington,Tx to Discuss Maint & Engineering Issues Related to turbine-driven & diesel-driven Auxiliary Feedwater Pumps Overspeed Events ML20153D7441998-09-21021 September 1998 Notification of 981006 Meeting with Util in Fort Calhoun,Ne to Discuss Common Cause Analysis ML20236X5111998-08-0606 August 1998 Notification of 980819 Meeting W/Omaha Public Power District in Rockville,Md to Discuss Fort Calhoun Station Refueling Outage Accomplishments,Challenges & Emerging Issues ML20236M9621998-07-0808 July 1998 Notification of 980723 Meeting W/Util in Arlington,Tx to Discuss Licensee Performance ML20249C6141998-06-22022 June 1998 Revised Notification of Licensee Meeting W/Util on 980710 to Discuss Switchyard Mods at Fort Calhoun Station ML20248L2961998-06-0505 June 1998 Notification of Significant Licensee Meeting W/Util on 980710 to Discuss Switchyard Mods at Fort Calhoun Station ML20247M1631998-05-14014 May 1998 Refers to GL 92-01,Rev 1,Supplement 1, Rv Structural Integrity, Issued in May 1995.RAI Re Plant 971013 Submittal of Revised Rv Weld Chemistry Valves Encl.Response Requested within 90 Days of Receipt of Ltr ML20217K3251998-04-28028 April 1998 Notification of 980505 Meeting W/Nebraska Public Power District in Arlington,Tx to Discuss Current Operations Dept Issues ML20203F7461998-02-23023 February 1998 Notification of 980309 Meeting W/Util in Arlington,Tx to Discuss Switchyard Mods at FCS ML20198E2091997-12-30030 December 1997 Requests Attached 4 Pages Be Placed in Docket File & Pdr. Suppl to 961120 Application to Amend Fort Calhoun License & Tss.Document Faxed Concurrence of License Commitment Re Relocation of Certain TS Requirements ML20199H2531997-11-24024 November 1997 Forwards Signed Original of Order Prohibiting Involvement in NRC-licensed Activities (Effective Immediately) Fs Bandy,For Transmittal to Ofc of Fr for Publication.W/O Encl ML20198Q2461997-10-31031 October 1997 Notification of 971113 Meeting W/Util in Rockville,Md to Discuss Issues Related to FCS Fire Protection Improvements, USAR Verification & OPPD Proposal for Submitting Substantial TS Changes in Lieu of Coverting to Std TS ML20217B4311997-09-22022 September 1997 Notification of 971007 Predecisional Enforcement Conference W/Util in Arlington,Tx to Discuss Disabling of Containment Spray Sys ML20210N8801997-08-21021 August 1997 Notification of Licensee Meeting W/Util on 970924 in Blair, Ne to Discuss Systematic Assessment of Licensee Performance. Meeting Open to Attendance by Members of General Public ML20217M0521997-08-14014 August 1997 Informs That Operator Licensing Exams Administered on 970414-0506 at Fort Calhoun,Unit 1.Listed Info for Processing Through Nudocs & Distribution to NRC Staff Including NRC PDR Also Encl ML20210J0951997-08-0505 August 1997 Informs That NRC Plans to Administer Gfes of Written Operator Licensing Exam at Facility on 971008.Requests That Listing of Names of Candidates for Exam Be Submitted to Listed Individuals by 970908 ML20141G9081997-07-0707 July 1997 Notification of 970721 Predecisional Enforcement Conference in Arlington,Texas to Discuss Apparent Violation of 10CFR50.65 Related to 970421 Steamline Rupture Event ML20138E3261997-04-29029 April 1997 Notification of Significant Licensee Meeting W/Util on 970505 to Discuss Steam Line Break,Root Cause Analysis & Corrective Actions ML20134P2231997-02-20020 February 1997 Discusses Ti 2515/122 Evaluation or Rosemount Pressure Transmitter Performance & Licensee Enhanced Surveillance Programs multi-plant Action B-122 ML20133H7781997-01-14014 January 1997 Notification of Significant Licensee Meeting W/Util on 970129 in Arlington,Tx to Discuss Issues Re Post-Accident Sample Sys ML20129E7041995-12-29029 December 1995 Forwards NRC Approved Operator Licensing Exam (Facility Outline & Initial Exam Submittal) for Tests Administered on 951204-08 ML20136A7871995-12-19019 December 1995 Partially Withheld Memo Discussing Petition Filed by Jf Doherty Requesting Six Plant Reactors Be Immediately Shutdown & Directors Decision 95-22 Which Denies Request NUREG-1299, Forwards Continuation of Curtiss Papers to Be Filed Under Commission Correspondence in Pdr.Advanced Copy Sent to Pdr. List of Documents Included in Four Boxes Encl1994-06-29029 June 1994 Forwards Continuation of Curtiss Papers to Be Filed Under Commission Correspondence in Pdr.Advanced Copy Sent to Pdr. List of Documents Included in Four Boxes Encl ML20059H8831994-01-24024 January 1994 Submits Daily Highlight Re 940127 Meeting W/Util in Rockville,Md to Discuss Plant Plans for Future Amends & Current Licensing Status ML20058K1231993-12-0202 December 1993 Forwards CS Wingo of FEMA Transmitting Final Exercise Rept for 930629 Exercise of Offsite Radiological Emergency Response Plans for Plant.Eight Deficiencies Noted During Exercise ML20057B3401993-09-13013 September 1993 Requests That NRR Provide Review of Concern Re Licensee TS Action Statement for Inoperable Channel for SIRWT Level to Determine If It Is Appropriate to Request Change Be Initiated to Plant TS ML20127E5081993-01-13013 January 1993 Notification of 930203 Meeting W/Util in Rockville,Md to Discuss Significant Plant Issues Such as Pts,Pra & Power Uprate & Current Status ML20126M2671992-12-24024 December 1992 Notification of Canceled 930107 Meeting in Rockville,Md Re Pressurized Thermal Shock,Probabalistic Risk Assessment & Plans for Future Power Uprate & Current Status.Proposed Agenda Encl ML20125B8211992-12-0404 December 1992 Notification of 921204 Meeting W/Util in Rockville,Md to Discuss Significant Plant Issues,Including Pts,Pra & Plan for Future Power Uprate & Current Status.Date Changed ML20128D1651992-11-24024 November 1992 Notification of 921209 Meeting W/Util in Rockville,Md to Discuss Significant Issues Such as Pts,Pra & Plans for Future Power Uprate & Current Status ML20055G4901990-07-16016 July 1990 Notification of 900726 Mgt Meeting W/Util in Omaha,Ne to Discuss SALP Rept 50-285/90-24 for May 1989 - Apr 1990 ML20198C4071990-06-22022 June 1990 Requests That NRR Review Basis of TS 2.16 to Determine If Basis Represents Nonconservative Approach to Safe Plant Operation ML20055C8721990-06-21021 June 1990 Notification of Significant Licensee Meeting W/Util on 900724 to Discuss Changes in Rev 6 of Examiner Stds & Exam Schedule for 1991 ML20248E8841989-10-0202 October 1989 Notification of 891005 Meeting W/Util in Region IV Ofc to Present Results of Licensee Evaluation of Delta T/Nuclear Power Deviation Anomaly 1999-08-27
[Table view] |
Text
,705 Y
- 4cg'o UNITED STATES p
"g
- J" o NUCLEAR REGULATORY COMMISSION .
- ;E WASHINGTON, D. C. 20555 g...../ May 5,1988 MEMORANDUM FOR
- Charles E. Rossi, Director Division of Operating Events Analysis TFPU: Lester Rubenstein, Assistant Director for Region IV Reactors and Special Projects Division of Reactor Projects - III, IV, V and Special Projects FR0tu Jose A. Calvo, Project Director Project Directorate IV Division of Reactor Projects - III, IV, V and Special Projects
SUBJECT:
FORT CALHOUN SAFETY INECTION AND REFUELING PATER TANK (SIRWT) LEVEL CETECTION During the recent meeting to discuss the status of Region IV plants, the failure of instrument air system check valves in the supply lines to the subject instrurentation was determined to need further reviw. Since your division was given the lead for the preparation of corre ience on the problen, the following information is being provided to a h -his effort.
This situation appeared when the licensee found that the check valves leaked excessively during testing. In order to conduct the test, the instrument air supply to the SIRUT bubblers was secured, and a nitrogen bottle was utilized to supply the ces pressure. When the licensee realized that the valve:were failing the test, the test setup with the N,, bottle was left in place to assure a reliable source of gas pressure remained 8vailable. Subsequently, the licensee found that the check valves that were installed were designed for high terperature water or steam service. Therefore, the valves were replaced with acceptable a newfor design employing air service the N,,(soft seats bottles haveand a spring-loaded been rewoved). If thedisctesting that is had not been perfonned and the vatves not replaced, it is possible that the Recirculation Actuation Signal (RAS) during a LOCA event would have prematurely transferred the suction of the High Pressure Safety Injection Pumps to the containment sump. Since an as-found leak rate test was not done on the original check valves, it is not possible to state just how long the air .
acevrulators would have rainteined the bubblers operable. Additionally, there I are other factors which could affect the air system availability such as the !
return of the air compressor after the load shedding sequence or the occurrence i of a coincident loss of off-site power. In these cases, the air supply source may be returned before a sufficient demand had been placed on the system to cause premature RAS actuation. In a worst case scenario assuming irr'ediate loss of air pressure, the high pressure pumps may not obtain suction from the sump. The pumps in this situation may fail in about two minutes without operator action. Since SIRWT remote level would also be lost, the operator must rely on containment surp level and injection duration to determine if an ,
1 override to return to SIRWT suction is appropriate.
l 8805160243 880505 i DR ADOCK 05000205 l g, PDR -
Charles E. Rossi The SIRWT level instrumentation is provided by an air bubbler system that determines tank level by sensing air backpressure. Two channels of tank level are provided with the air pressure being converted to an analog level signal by a local transmitter. Separate from this level detection is a set of four bubblers which have Static-0-Ring pressure switches that are used to provide the low tank level input into the Pecirculation Actuation Signal set-up circuitry. The 31RWT low level (tank level of 16 in.) signal combines with either the Pressurizer Pressure Low signal (PPLS) or the Containment Pressure High signal (CPHS) to set-up the RAS. The RAS performs the function of securing the low pressure safety injection pumps and transferring suction for the High Pressure Safety Injection and the Containment Spray Pumps from the SIRWT to the containment sump. Although the initiation of RAS is annunciated in the control room, no direct level readings are available from this portien of the circuit. The analog level transmitters have both high and low level alarm functions also annuciated in the control room.
Since both the tank level instrumentation art the low tank level input device for RAS set-up require instrument air, events which affect the status of the air supply have a possible consequence on their function. In addition to the obvious loss of the instrument air compressors during a loss of off-site power event, the compressors are deenergired during a load shedding secuence in a loss of coolant event. Because of this possibility, the SIRWT low level switches for RAS were designed with a supply of air that is guaranteed by the incorporation of instrument air supply check valves tc isolate the bubblers upon loss of air pressure and the use of air accumulators. The problem noted by the licensee, however, was that during leak testing, each of these valves leaked excessively. This would have resulted in a bleeding down of the air pressure in the accumulators at a rate determined by the residual pressure in ,
the instrunent air system. The prenature bleeding down of the bubbler air I supply could cause the actuation of the low level input into the RAS set-up circuit at a premature time. Sirce the analog level instrurents do not utilize air accumulators, the function of these instruments is not maintained when the instrument air pressure is lost. Depending on the leakage and demand on the instrument air system, the length of time that air will be available will vary.
The PAS input will occur when the air pressure drops to approxirately 0.5 psig, and the level indication will trend down as pressure decreases. The low level alarm will be received as sensed level reaches 186 inches.
The consequences of an event which requires the initiation of safety injection will change fron that analy7ed if the time of inititation of the RAS signal is premature. Transient analysis for the Loss of Coolant Accidents assume that a specified cuantity of SIRWT water of a specified boron concentration and temperature is injected. A prenature RAS will secure the low pressure injection pumps and shift the high pressure safety injection pumps to a recirc-ulation mode. This may occur at a time which is insufficient to allow proper suction to be established from the sump. Since the RAS also cause the mini-flow ,
recirc lines back to the SIRWT to shut, the high pressure pumps may fail within I two minutes due to insufficient flow for cooling if suction cannot be estab- !
lished. Although the RAS circuit design has a means to override the signal and realign the valves, the loss of instrunent air fails the SIRWT control roem l I
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Charles E. Rossi level instruments low such that the operator will not know true level. His only information is that the time to drawdown the tank should be about 20 ninutes.
An early RAS would be indicative of an instrument problem or a major loss of water inventory.
In the case of Fort Calhoun, the instrument air system is not classified as !
safety-related. Also, the air isolation check valves are not required to be tested during surveillance or inservice testing or periodically inspected.
This fact was first addressed by a Safety System Outage Modification Inspection (SSOMI) in September 1986. The need to verify the condition and functionally of this valves was further highlighted during the water ingress I into the instrument air system event on July 6, 1987. Subsequently, the licensee has agreed to periodically leak test various air supply check valves.
If you should need further assistance in the preparation of the Information !
Notice on this subject, please contact Patrick Milano, on ext. 21347. )
1 Jose A. Calvo, Project Director Project Directorate IV Divisicn of Reactor Projects - III, IV, V and Special Projects cc: T. Murley J. Sniezek F. Miraglia D. Crutchfield G. Holahan W. Jensen DIJTRIBUTION
\ POCKET FILE NRC & LOCAL PDRs PD4 READING FILE i DCRUTCHFIELD l GHOLAHAN PN00 NAN ABOURNIA OGC JCALVO EJORDAN l JPARTLOW -
ACRS (10) .
r .-
- See previous concurrences: 7_
F04/BFM* PD4/PM* PD4/D / @ DR4A PMilano ABournia JCalvo LRubenstein 4/29/88 4/29/88 r // v/88 4/ f-/88
1 level instruments low such that the opeator will not know true level. His only I information is that the time to drawdown the tank should be about 20 minutes.
An early RAS would be indicative of an instrument problem or a major loss of water inventory. '
In the case of Fort Calhoun, the instrument air system is not classified as safety-related. Also, the air isolation check valves are not reqfuired to be tested during surveillance or inservice testing or periodically inspected.
This fact was first addressed by a Safety System Outage Modii ation l Inspection (SSOMI) in September 1986. The need to verify the condition and .
functionally of this valves was further highlighted during );he water ingrees into the instrument air system event on July 6, 1987. Sub equently, the licensee has agreed to periodically leak test various air supply check valves.
If you should need further assistance in the preparati of the Infonnation Notice on this instrumentation, please feel free to c tact Patrick Milano.
Jose A. Cy vo, Project Director I Project irectorate IV l Divisio of Reactor Projects - III, IV, and Special Projects cc: T. Murley ,
J. Sniezek i F. Miraglia l
- 0. Crutchfield G. Holahan W. Jensen l P. Milano 1 I
DISTRIBUTION DOCKET FILE NRC & LOCAL PDRs PD4 READING FILE I DCRUTCHFIELD GHOLAHAN PN00 NAN ABOURNIA OGC_ _ j ggy , j E0RDAN ./ I JPARTLOW /
ACRS (10) /
i l
QO v / q c ~)--~
PD4/ BPM PD4/PM PD4/D PMilano
/
/ ABournia JCalvo 4/8/88 4/11/88 4/ /88 (4[omm.J f / pp i
-,e-,-, -m-- _-ee- , _ nn n e -y_--a. ye,,,-, gew--.- ogswe,,r m en wm-,-,,gm
Charles E. Rossi level instruments low such that the operator will not know true level. His only information is that the time to drawdown the tank should be about 20 minutes.
An early RAS would be indicative cf an instrument problem or a major loss of water inventory.
In the case of Fort Calhoun, the instrurent air system is not classified as safety-related. Also, the air isolation check valves are not reouired to be tested during surveillance er inservice testing or periodically inspected.
This fact was first addressed by a Safety System Outage Modification Inspection (SS0MI) in September 1986. The need to verify the condition and functionally of this valves was further highlighted during the water ingress into the instrurent air system event on July 6,1987 Subsequently, the licensee has acreed to periodically leak test various air supply check valves.
If ycu should need further assistarcs in the preparation of the Information Notice on this subject, please contact Patrick Milano, on ext. 21347.
kc Lt, b. [ W
/ ose J A. Calvo, Project Director Project Directorate IV Division of Reactor Projects - III, IV, V and Special Projects cc: T. Murley J. Sniezek F. Miraglia D. Crutchfield G. Holahan W. Jensen j l
1 I
l l
i I
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