ML20248C524

Forwards Evaluation of Seismic & Other External Events Related Portions of Info Submitted by Licensee of Millstone Unit 3 in Response to GL 88-20,suppl 4,individual Plant Exam for External Events

ML20248C524
Person / Time
Site:	Millstone
Issue date:	05/02/1995
From:	Shao L NRC OFFICE OF NUCLEAR REGULATORY RESEARCH (RES)
To:	Hodges W NRC OFFICE OF NUCLEAR REGULATORY RESEARCH (RES)
Shared Package
ML20248C400	List: ML20248C413 ML20248C524 ML20248C545 ML20248C563 ML20248C573 NUREG-1407, Forwards Staff Evaluation of Millstone Unit 3,individual Plant Exam of External Events Submitted on 911223 Re Response to GL 88-20 .Util Capable of Identifying Severe Accidents & Vulnerabilites & Met GL 88-20,Suppl 4
References
GL-88-20, NUDOCS 9806020178
Download: ML20248C524 (2)

Text

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. May 2. 1995 MEMORANDUM To: Wayne M. Hodges, Director Division of Systems Technology, RES FROM: Lawrence C. Shao, Director /s/LCShao Division of Engineering Technology, RES

SUBJECT:

STAFF EVALUATION REPORT OF MILLSTONE UNIT 3 IPEEE SUBMITTAL Attached is our evaluation of seismic and other external events j related portions of information submitted by the licensee of Millstone Unit 3 in response to Generic Letter 88-20, Supplement 4, Individual Plant Examination for External Events (IPEEE). We i have not reviewed fire related portions.

The licensee's 1990 IPEEE submittal has relied on the 1983 probabilistic safety study (PSS) conducted for Millstone Unit 3.

Since the staff had reviewed the PSS and issued an Risk Evaluation Report, the current staff evaluation supplements the earlier evaluation to draw conclusions with respect to objectives of an IPEEE.

In summary, we conclude that the licensee's studies conducted in support of IPEEE meet the intent of the generic letter. The one potential seismic vulnerability to Millstone 3 identified by the staff was taken care of by the licensee through hardware i

replacement, and is, therefore, considered by the staff to be resolved.

The attached staff evaluation was prepared by T. Y. Chang of the Division of Engineering Technology. Please contact him or N.

Chokshi should you have any questions.

Attachment:

As stated cc w/att:

E. Beckjord D. Morrison

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T. Speis DISTRIBUTION:

Branch r/f C. Serpan P. Kadambi RES 2C-5 M. Drouin LCS (Sig File)

J. Murphy J. Chen M. Cunningham G. Bagchi i

l DOCUMENT NAME: P:\ MILLS 3.SER T. r: w a ,y . mi. s um.nt, inse.t. in v. 6. : c . coy wmout ensio.ur . cwy we .noiosure. r . No se /

OFFIP.E GSIB:RES r SGEB:RES c SGEB:RES c DD:DET:RES l N D:R4+1&S l N NAME TChang* NChokshi* AMurphy* JCraig* LShao DATE 4/26/95 4/26/95 4/26/95 4/26/95 5/ / /95 l

• see previous concurrence I

[ 0FFICIAL RECORD COPY l 9806020178 980526

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l MILLSTONE UNIT 3 OUTLINE OF STAFF EVALUATION REPORT ON IPEEE EEYTEM

1.0 BACKGROUND

2.0 SEISMIC EVENTS 2.1 MILLSTONE 3 PSS Results 2.2 Methodoloav 2.3 GL 88-20. Sucolement 4 Enhancements 2.3.1 Hazard Selection 2.3.2 Plant Walkdowns 2.3.3 Relay Chatter 2.3.4 Liquefaction 2.3.5 HCLPF Calculations 2.4 Containment Performance 2.5 Staff Conclusions 3.0 EXTERNAL FLOODS 3.1 MILLSTONE 3 PSS Results I

3.2 Staff Conclusions 4.0 OTHER EXTERNAL EVENTS 4.1 MILLSTONE 3 PSS Results 4.1.1 High Winds 4.1.2 Aircraft Crash g 4.1.3 Transportation and Other External Hazard j i

4.2 Staff Conclusions I

, 5.0 CVERALL STAFF CONCLUSIONS

6.0 REFERENCES

1 I

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