ML17174A430
| ML17174A430 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 01/16/1980 |
| From: | Noonan V Office of Nuclear Reactor Regulation |
| To: | Ippolito T Office of Nuclear Reactor Regulation |
| References | |
| TASK-06-02.A, TASK-6-2.A, TASK-RR 12625, NUDOCS 8002120043 | |
| Download: ML17174A430 (4) | |
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JAN 1 6 19ao
'MEMORANDUM FOR:. t*. I ppo 1i to, Chief, ORB3, DOR
-~'
FROM:
V. s. Noonan, thief,-*Engineering Branch, DOR
SUBJECT:
COMMONWEALTH. EDISON COMPANY, TECHNICAL SPECIFICATIONS REVISION Pl ant:. Dresden Uni ts Nos. 2 and 3 Licensing No.: 'DPR-19 and DPRl';a5 Docket Nos~ : 50-237 and 50-~ ~ 'f-'1 -.
.Branch and Project ~ah~ger:* ORB #3, ~. Bevan Description of Task:
TAC #12625 and #12626 Rev_iew State: Complete. -
The.Engineering Branch, Division of Operating-Reactors, has reviewe~ the information submitted_ by Commonwealth Edison-Company 'dated January 2, 1980
- on*a p~oposed.re~i~ion to the Technic~l Specifications to facilitate the~
torus support modification *. Th~ evaluation and concl~sions are attached.
Please mak~ the appropriate input to RAMs for the completion 6f the l~censing actions*.
The long term Mark I suction header analysis shoul_d be performed for these plants as expeditiously as* possible so the capab*ility of the torus ring
- header to with stand the.. torus-hyd.rodynamic lOad i ngs can be substantiated.
Enclsoure:
As stated
Contact:
H*. Shaw
- 27364 cc: o *. Eisenhut R. *oiedesco L.
- Shao
- v. Noonan.
I<. R * ~Ji chman
- H. K~;.Shm*1'
- . J.-: Fafr,
Original signed. bil.
~ Vincent*s. Nbonan, Chief Engineering Branch Diviston of Operating Reactors
- .. *<, : $ 0'021 ~~fJO'f3*..
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-NJlC PO~ 318 (9-76) NRCM 0240 l
UNITED STATES
-1\\JUCLEAR REGULATORY COMMISSW°\\I WASHINGTON, 0. C. 20555
-JAN 1 6 1980 MEMORANDUM FOR:
T. Ippolito, Chief, ORB3, DOR FROM:
V. S. Noonan, Chief, Engineering Branch, DOR
SUBJECT:
COMMONWEALTH EDISON COMPANY, TECHNICAL SPECIFICATIONS REVIS ION Plant: Dresden Units Nos. 2 and 3 Licensing No.: DPR-19 and DPR-25 Docket Nos.:
50-237 and 50-240 Branch and Project Manager:
ORB #3, R. Bevan Description of Task:
TAC #12625 and #12626 Review State: Complete The Engineering Branch, Division of Operating Reactors, has reviewed the information submitted by Commonwealth Edison Company dated January 2, 1980 on a proposed revision to the Technical Specifications to facilitate the torus support modification.
The evaluation and conclusions are attached.
Please make the appropriate input to RAMs for the completion of the licensing actions.
1 The long term Mark I suction header analysis should bS performed for these plants as expeditiously as possible so the capability of the torus ring header to. \\vithstand the torus hydrodynamic loadin s can be substantiated.
Enclsoure:
As stated
Contact:
H. Shaw 27364 cc:
D. Eisenhut R. Tedesco L. Shao V. Noonan K. R. \\.Jichman H. K. Shaw J. Fair R. Bevan
.... ~......
DRESDEN UNITS 2 AND 3 PROPOSED CHANGES TO THE TECHNICAL SPECIFICATION ENGINEERI~G BRANCH DIVISION OF OPERATING REACTORS Introduction Commonwealth Edison Company has proposed three changes to the Technical Specification for Dresden Units 2 and 3.
The proposed changes will allow the torus ring header snubbers to be inoperable in groups of up to three (3) pairs at the same time until July 1, 1980, so the installation of Mark I torus support modifications can be facilitated.
Description Three changes are proposed to the Technical Specifications for Dresden Units 2 and
- 3.
Proposed change I is to add the following sentence to the end of paragraph 3.6.I.2;
Torus ring header snubbers may be inoperable in groups of up to three (3) pairs until July 1, 1980 to facilitate the installation of Mark I Torus Support Modifica-tions."
Proposed change II is to add the following sentence to the end of paragraph 3.6.I.4; "This requirement does not apply to torus ring header snubbers for the period identified in paragraph 3.6.I.2 above."
Proposed change III is to add the following paragraph to page 99a, right column -
as the next to last paragraph.
"A re-analysis of the ring header design based* upon acceleration* response spectra derived from the original suction header analysis report demonstrates that for normal operation plus seismic, neither the header nor the torus penetrations are over-stressed with all snubbers inoperable; the limitation of a maximum of three pairs inoperable out of six pairs is considered conservative.
Since the analysis shows that the plant can operate safely indefinitely with no snubbers on the ring header, the limitation on operation and startup with three inoperable pairs until July 1, 1980 is justified. This time frame is adequate to allow completion of Mark I external structural \\vork."
Evaluation and Conclusion There are six (6) pairs of snubbers in the torus ring header supporting system for both Dresden Units 2 and 3. The snubbers are used for the seismic protection for the torus ring header.
However, a re-analysis of the ring header design based upon acceleration reponse spectra derived fbrm the original suction header analysis report demonstrated that for normal operation plus seismic loading, the header and the torus penetrations will not be over-stressed in the supporting system even if all six pairs of snubbers are inoperable. Therefore, the limitation of a maximum of three pairs of inoperable snubbers on operation and startup until July 1, 1980 is justified. The proposed changes to the technical Specification should be permitted.
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JAN 2 11980