B11794, Submits for Review,Integrated Safety Assessment Program Topics 1.16.1, MP1/MP2 Backfeed, 1.16.2, Modify CRD Pumps, 1.16.3, Alternative Cooling for Shutdown Equipment, & 1.16.4, Power Cold Shutdown Equipment

Submits for Review,Integrated Safety Assessment Program Topics 1.16.1, MP1/MP2 Backfeed, 1.16.2, Modify CRD Pumps, 1.16.3, Alternative Cooling for Shutdown Equipment, & 1.16.4, Power Cold Shutdown Equipment

ML20133M702
Person / Time
Site:	Millstone
Issue date:	10/16/1985
From:	Opeka J, Sears C NORTHEAST NUCLEAR ENERGY CO., NORTHEAST UTILITIES
To:	Charemagne Grimes Office of Nuclear Reactor Regulation
References
B11794, GL-85-01, GL-85-1, NUDOCS 8510280203
Download: ML20133M702 (14)

Text

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• Seiden Street. Berhn. Connecticut h s m...e s e r=c cw- P O BOX 270 e .. a .u . c-~

H ARTFORD. CONNECTICUT 06141-0270 k k J (([C))'C; (203) 665-s000 October 16, 1985 Docket No. 50-245 Bil794 Director of Nuclear Reactor Regulation Attn: Mr. Christopher I. Grimes, Chief Systematic Evaluation Program Branch U.S. Nuclear Regulatory Commission Washington, D.C. 20555

References:

(1) J. F. Opeka letter to C. I. Grimes, dated May 17, 1985.

(2) H. L. Thompson letter to J. F. Opeka, dated July 31, 1935.

Gentlemen:

Millstone Nuclear Power Station, Unit No.1 Integrated Safety Assessment Program In Reference (1), Northeast Nuclear Energy Company (NNECO) provided a proposed scope for the Integrated Safety Assessment Program (ISAP) review of Millstone Unit No.1. In Reference (2), the Staff formally issued the results of the ISAP screening review process, establishing the scope of ISAP for Millstone Unit No. I and initiating issue-specific evaluations. Reference (1) also indicated that for each issue or topic included in ISAP, NNECO would provide a discussion of the safety objective and an evaluation of the plant design with respect to the issue being addressed to identify specific items to be considered in the integrated assessment. In accordance with this commitment, reviews for the following ISAP topics are attached:

o ISAP Topic 1.16.1 "MPl/MP2 Backfeed" o ISAP Topic 1.16.2 " Modify CRD Pumps" o ISAP Topic 1.16.3 " Alternative Cooling for Shutdown Equipment" o ISAP Topic 1.16.4 " Power Cold Shutdown Equipment" If you have any questions concerning the attached reviews, please contact us.

Very truly yours, NORTHEAST NUCLEAR ENERGY COMPANY 851028 M03 851016

d. O pt M.

PDR ADOCK 05000245 3* F* 0P eka' F PDR Senior Vice President

'O1 By: C. F. Sears Vice President cc: J. A. Zwolinski Ao0' or,

Docket No. 50-245 ISAP TOPIG- nod.16.1 MPl/MP2 BACKFEED MODIFICATION October,1985

)

IS AP Topic No. l.16.1 l l MPl/MP2 Backfeed Modification  ;

!. Introduction This topic resulted from the review of proposed exemption requests and modifications submitted for Millstone Unit No. I to comply with 10CFR50.48 and Appendix R to 10CFR50. One of the proposed modifications to comply with Appendix R is to use a Millstone Unit No. 2 diesel generator to supply emergency power capability to Millstone Unit No. I during a control room or turbine building fire. Similarly, the backfeed capability would allow Unit I to supply Unit 2 with shutdown j power for a Unit 2 control room fire. This proposed modification is presently under review by the NRC Staff and is expected to be approved in the Appendix R Safety Evaluation Report (SER). The SER is scheduled to

! be issued in 1985.

j I

II. Review Criteria

1. 10CFR50.48

2. 10CFR50, Appendix R

3. Standard Review Plan Section 9.5.1

[

4. Branch Technical Position APCSB 9.5-1, Appendix A i

5. Regulatory Guide 1.120

6. Section 8.13 of Enclosure 6 to Generic Letter 85-01 provides a ,

i Complete List of Pre-1985 NRC Guidance Documents

7. NFPA Code

8. ASTM E-Il9 Ill. Related Projects / Interfaces Topic No.1.16.2 Modify CRD Pumps Topic No.1.16.3 Alternate Cooling for Shutdown Cooling

! Topic No.1.16.4 Power Cold Shutdown Equipment j Topic No.1.02 Tornado Missile Protection i

l IV. Evaluation j The on-site emergency AC power system for Millstone Unit No. I consists

! of one diesel generator and one gas turbine generator with associated

! distribution equipment. The review criteria in Section II were used by the

] NRC Staff in their review of the proposed modification to use a Millstone Unit No. 2 diesel generator to supply emergency power to Millstone Un-t No. I during a control room or turbine building fire. A draf t SER supplied i with Reference I concluded the modification was acceptab!c to compensate for shutdown functions damaged by a fire and will meet current licensing criteria.

i j

I

At the present time Millstone Unit No. I does not comply with the current criteria f Appendix R. The implementation schedule of 10CFR50.48 for modifi itions required to comply with Appendix R has been tolled until the NRC taff issues an SER on Appendix R. Additional information has been pros Jed in Reference 2, 3 and 4 to assist the Staff in their continuing review.

V. Conclusions The proposed modification to use a Millstone Unit No. 2 diesel generator to supply emergency power to Millstone Unit No. I during a control room or turbine building fire is awaiting NRC Staff approval. The Staff has recommended approval of this modification in a draf t SER supplied with Reference 1. Although 10CFR50.48 provides an explicit implementation date for this modification, the expected safety impact and a priority for i

implementation should be determined in the integrated assessments.

VI. References f

1. 3. A. Zwolinski letter to 3. F. Opeka, dated July 26, 1985.

2. 3. F. Opeka letter to H. L. Thompson, Jr., dated August 7,1985.

3. 3. F. Opeka letter to H. L. Thompson, Jr., dated August 23,1985.

4. W. G. Counsil letter to D. G. Eisenhut, dated December 4,1984.

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i Docket No. 50-2/45 i

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1 ISAP TOPIC NO.1.16.2 MODIFY CRD PUMPS 1

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1 October,1985

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ISAP Topic No.1.16.2 Modify CRD Pumps I. Introduction This topic resulted from the review of proposed exemption requests and modifications submitted for Millstone Unit No. I to comply with 10CFR50.48 and Appendix 'l to 10CFR50. One of the proposed modifications to comply with Appendix R is to modify the CRD pumps to operate without an external source of cooling water during a control room or turbine building / intake structure fire. The CRD pump will be used to compensate for any decrease in . reactor vessel water level due to leakage and shrinkage during cooldown. This pcoposed modification is presently under review by the NRC Staff and la expected to be approved in the Appendix R Safety Evaluation Report (SER). The SER is scheduled to be issued in 1985.

II. Review Criteria

1. 10CFR50.48

2. 10CFR50, Appendix R

3. Standard Review Plan Section 9.5.1

4. Branch Technical Position APCSB 9.5-1, Appendix A

5. Regulatory Guide 1.120

, 6. Section 8.13 of Enclosure 6 to Generic Letter 35-01 provides a complete list of pre-1985 NRC guidance documents

7. NFPA Code

8. ASTM E-119 III. Related Projects / Interfaces The following ISAP topics were related to the CRD pump modifications:

Topic 1.16.1 MPl/MP2 Backfeed Topic 1.16.3 Alternate Cooling for Shutdown Cooling Topic 1.16.4 Power Cold Shutdown Equipment IV. Evaluation A serious fire in the control room or turbine building could result in damage to numerous control and power cables. To comply with Appendix R it was assumed that all cooling water systems would be lost and that a station blackout situation exists. Corrective actions for this scenario consist of scramming the reactor and initiating isolation condenser operation. Af ter a decay heat removal path has been established via the isolation condenser, the Millstone Unit No. 2 emergency power is aligned to a Unit No.1 CRD pump. The CRD pump will be used to compensate for any decrease in reactor vessel water level due to leakage and shrinkage during cooldown.

After the fire has been extinguished, the shutdown cooling system is repaired to cool the plant to cold shutdown. )

j- . .

l 4 The NRC Staff used the review criteria in Section 11 to evaluate the

, proposed modification to operate the CRD pumps without an external 4 source of cooling water during a control room or turbine building / intake structure fire. The NRC Staff is expected to approve this proposed modification in the Appendix R SER. A draft SER supplied with Reference I concluded the modification was acceptable to compensate for i shutdown functions damaged by a fire and will meet current licensing

! criteria.

4 At the present time Millstone Unit No. I does not comply with the current criteria of Appendix R. The implementation schedule of 10CFR50.48 for j modifications required to comply with Appendix R has been tolled until the

NRC Staff issues an SER on Appendix R. Additional information was provided in References 2, 3 and 4 to assist the Staff in their continuing review.

1 V. Conclusions l The proposed modification to operate the CRD pumps without an external

source of cooling water during a control room or turbine building / intake structure fire is awaiting NRC Staff approval. The Staff has recommended j approval of this modification in a draf t SER supplied with Reference 1.

! Although 10CFR50.48 provides an explicit implementation date for this j modification, the expected safety impact and a priority for implementation should be determined in the integrated assessment.

i VI. References i

1. 3. A. Zwolinski letter to 3. F. Opeka, dated July 26, 1985.

l 2. 3. F. Opeka letter to H. L. Thompson, Jr., dated August 7,1985.

t

3. 3. F. Opeka letter to H. L. Thompson, Jr., dated August 23,1985.

! 4. W. G. Counsil letter to D. G. Eisenhut, dated December 4,1984.

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4 Docket No. 50-245 ISAP TOPIC NO.1.16.3

)

ALTERNATE COOLING FOR SHUTDOWN COOLING i

October,1985

ISAP Topic No.1.16.3 Alternate Cooling for Shutdown Cooling I. Introduction This topic resulted from the review of proposed exemption requests and modifications submitted for Millstone Unit No. I to comply with 10CFR50.48 and Appendix R to 10CFR50. One of the proposed modifications to comply with Appendix R is to modify portions of the shutdown cooling (SDC) system to allow the plant to be cooled to cold shutdown conditions without the use of service water. This will entail j modifying the reactor building closed cooling water (RBCCW) connections 4 on the SDC pumps and heat exchangers to accept fire hoses. The fire protection system will provide an alternate means of supplying cooling water. This proposed modification is presently under review by the NRC Staff and is expected to be approved in the Appendix R Safety Evaluation Report (SER). The SER is scheduled to be issued in 1985.

II. Review Criteria

1. 10CFR50.48

2. 10CFR50, Appendix R

3. Standard Review Plan Section 9.5.1

4. Branch Technical Position APCSB 9.5-1, Appendix A

5. Regulatory Guide 1.120

6. Section 3.13 of Enclosure 6 to Generic Letter 85-01 provides a Complete List of Pre-1985 NRC Guidance Documents

7. NFPA Code

8. ASTM E-119 i

III. Related Projects / Interfaces The following ISAP topics are related tc the alternate cooling for SDC modifications:

Topic No.1.16.1 MPl/MP2 Backfeed Modifications Topic No.1.16.2 Modify CRD pumps Topic No.1.16.4 Power Cold Shutdown Equipment 1

IV. Evaluation i A serious fire in the control room or turbine building / intake structure could result in damage to numerous control and power cables. To comply with Appendix R it was assumed that all cooling water systems would be lost and that a station blackout situation exists. Corrective actions for this scenario consist of scramming the reactor and initiating condenser a .- -- , _, , _ . . , . . , , - . . . , , ~n _, ---.-_.nn. ,_...___,w__n , . _ , . , , . , , . c_ .- . . ,_ _ , . . _ . . . . , . ..

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operation. Af ter a decay heat removal path has been established via the isolation condenser, the Millstone Unit No. 2 emergency power is aligned to a Unit No.1 CRD pump. The CRD pump will be used to compensate for any decrease in reactor vessel water level due to leakage and shrinkage during cooldown.

After the fire has been extinguished, fire water will be supplied to the SDC pump motors and the secondary side of the SDC heat exchangers for cooling. Repairs will be implemented to ensure that the plant can 6e put into coli shutdown within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.

The NRC Staff used the review criteria in Section II to evaluate this proposed modification. The NRC Staff is expected to approve this proposed modification in the Appendix R SER.

At the present time Millstone Unit No. I does not comply with the current criteria of Appendix R. The implementation schedule of 10CFR50.48 for modifications requi.ed to comply with Appendix R has been tolled until the NRC Staff issues an SER on Appendix R. Additional information was provided in References 2, 3 and 4 to assist the Staff in their continuing review.

V. Conclusions The proposed modification to supply fire water to cool the SDC pump motor and the secondary side of the SDC heat exchangers during a turbine building / intake structure or reactor building fire is awaiting NRC Staff approval. Although 10CFR50.48 provides an explicit implementation date for this modification, the expected safety impact and a priority for implementation should be determined in the integrated assessment.

VI. References

1. 3. A. Zwolinski letter to 3. F. Opeka, dated July 26, 1985.

2. 3. F. Opeka letter to <1. L. Thompson, Jr., dated August 7,1985.

3. 3. F. Opeka letter to H. L. Thompson, Jr., dated August 23, 1985.

4. W. C. Counsit letter to D. G. Eisenhut, dated December 4,1984.

i Docket No. 50-2/45 ISAP TOPIC NO.1.16./4 POWER COLD SHUTDOWN EQUIPMENT i

October,1985 l

4

) ISAP Topic No.1.16.4 Power Cold Shutdown Equipment i I. Introduction This topic resulted from the review of proposed exemption requests and '

modifications submitted for Millstone Unit No. I to comply with 10CFR50.48 and Appendix R to 10CFR50. One of the modifications 1

proposed to comply with Appendix R is to protect the three drywell

penetrations in the shutdown cooling (SDC) pump cubicle that contain power and control cables to the SDC system isolation valve (1-SD-1), the primary containment inner isolation steam inlet valve (1-IC-1) and the primary containment inner isolation condensate return valve (1-lC-4).

Repair procedures will be developed to provide a source of emergency power to the MOVs after a reactor building fire. This proposed modification is presently under review by the NRC Staff and is expected to be approved in the Appendix R Safety Evaluation Report (SER). The SER is scheduled to be issued in 1985.

11. Review Criteria

1. 10CFR50.48

2. 10CFR50, Appendix R

3. Standard Review Plan Section 9.5.1

4. Branch Technical Position APCSB 9.5-1, Appendix A

5. Regulatory Guide 1.120

6. Section 8.13 of Enclosure 6 to Generic Letter 85-01 provides a

Complete List of Pre-1985 NRC Guidance Documents t

7. NFPA Code

8. ASTM E-Il9 111. Related Projects / Interfaces The following ISAP topics are related to the modifications to power cold j shutdown equipment.

i Topic 1.16.1 MPl/MP2 Backfeed Modifications Topic 1.16.2 Modify CRD Pumps Topic 1.16.3 Alternate Cooling for Shutdown Cooling IV. Evaluation A serious fire in the reactor building or turbine building could reruit in damage to numerous control and power cables. To comply with Appendix R it was assumed that all coo:ing water systems would be lost and that a

, station blackout situation exists. Corrective actions for a turbine building

fire consist of scramming the reactor and initiating isolation condenser operation. Af ter a decay heat removal path has been established via the isolation condenser, the Millstone Unit No. 2 emergency power is aligned to a Unit No.1 CRD pump. The CRD pump will be used to compensate for any decrease in reactor vessel water level due to leakage and shrinkage during cooldown.

Af ter the fire has been extinguished in the turbine building, the shutdown cooling system will be required to cool the plant to cold shutdown. Power for the SDC pump and valve 1-SD-1 will be supplied from a Millstone Unit No. 2 emergency bus. Plant modifications and procedures will be prepared and repair materials provided to ensure that the plant can be put into cold shutdown within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.

For fire protection purposes, the reactor building is divided into two fire zones. These are the shutdown cooling pump cubicle and the balance of the reactor building. A fire in the shutdown cooling pump cubicle will not result in damage to the balance of the reactor building.

The plant will be placed into cold shutdown by using the LPCI system to recirculate water from the torus, through the LPCI heat exchangers, and into the reactor vessel. Reactor coolant will be returned to the torus via the ADS valves.

For a fire in the balance of the reactor building, the reactor will be scrammed and decay heat removal will initially be through relief of steam via the safety relief valves to the torus. The Feedwater Coolant Injection System (FWCI) will be used to maintain reactor vessel water level.

After the fire has been extinguished in the reactor building, isolation condenser operability will be restored by manually opening the isolation valves outside the drywell and providing emergency power for isolation valves 1-IC-1 and 1-lC-4 inside the drywell. The isolation valves are assumed to have spuriously closed. To achieve cold shutdown, repairs will be made to the SDC system pump motor cables and isolation valve cables similar to the actions required for IC valves I-IC-1 and 1-IC-4.

The NRC Staff used the review criteria in Section 11 to evaluate tha proposed modifications during a turbine building or reactor building fire.

The NRC Staff is expected to approve this proposed modification in the Appendix R SER.

At the present time Millstone Unit No. I does not comply with the current criteria of Appendix R. The implementation schedule of 10CFR50.48 for modifications required to comply with Appendix R has been tolled until the NRC Staff issues an SER on Appendix R. Additional information was provided in References 2, 3 and 4 to assist the Staff in their continuing review.

V. Conclusion The proposed procedures to provide emergency power for SDC system isolation valve and motor cables, the primary containment inner isolation

steam inlet valve cables and the primary containment inner isolation condensate return valve cables during a reactor building fire is awaiting NRC Staff approval. Although 10CFR50.48 provides an explicit implementation date for this modification, the expected safety impact and a priority for implementation should be determined in the integrated assessment.

' VI. References

1. 3. A. Zwolinski letter to 3. F. Opeka, dated July 26,1985.

2. 3. F. Opeka letter to H. L. Thompson, Jr., dated Augu ;t 7,1985.

3. 3. F. Opeka letter ta H. L. Thompson, Jr., dated August 23,1985.

4. W. G. Counsil letter to D. G. Eisenhut, dated December 4,1984.

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