ML20008F400
| ML20008F400 | |
| Person / Time | |
|---|---|
| Site: | Zion File:ZionSolutions icon.png |
| Issue date: | 03/05/1981 |
| From: | Tramm T COMMONWEALTH EDISON CO. |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8103130241 | |
| Download: ML20008F400 (3) | |
Text
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Commonw:dth Edison O. oce F,rst National Plaza C$capo. Upnois O
Accress Reply to Post Office Box 167 Cbcago. Dhnois 60690
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March 5, 1981 i
44 Mr. Harold R. Denton, Director 8
5 Office of Nuclear Reactor Regulation 4
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U.S. Nuclear Regulatory Commission k
Washington, D. C.
20555 g
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Subjec':
Zion Station Units 1 and 2 Additional Information for use of 90d-Exchange Technique at Zion Station NRC Docket Nos. 50-295 and 50-304
References:
1)
February 4, 1981 letter from J. S.
Abel to H.
R. Denton titled "Use of Rod-Exchange Technique i
for Rod Worth Measurements at Zion Station".
1 2)
February 11, 1981 letter (NS-TMA-2392) from T.
1 M. Anderson to J. R. Miller formally outlining the Generic Rod-Exchange Technique Program Topical.
3)
March 6, 1981 letter (NS-TMA-2405) from T. M.
Anderson to J. R.
Miller.
i Oear Mr. Denton:
Commonwealth Edison Company hereby supplements the information relateo to use of-the rod-exchange technique at Zion Station (Reference 1).
Per discussion with your Staff on February 5,
- 1981, Commonwealth Edison was requested to provide additional information regarding corrective action to be taken whenever test results do not meet the design and/or acceptance criteria.
In addition, the NRC Staff required a reference to a Westinghouse generic topical report on the subject method or the submittal of a Commonwealth Edison topical-report specific to Zion Station.
Commonwealth Edison's response to these requests follows.
Failure to meet a-rod-exchange program design criterion provided in Reference 1 coes not constitute an unreviewed safety question since tne design criteria are more restrictive than the Technical Specification and safety criterion.
The design criteria are basec on the present state of the art of design techniques and methods.
They are viewed as a guide to p m ible measurement or design-While ef forts should be taken to resolve any conflict errors.
between measurement and prediction, the design criteria are not considered inviolaole.
8108130%.
. If a design criterion is not met, an investigation will be performed Dy on-site and appropriate off-site nuclear design personnel.
Inis investigation will incluce consideration of plant startup data and the applicaDility of reload safety analysis.
The results of this investigation will be useo to improve future design and/or testing methods.
If the rod exchange saiety criterion provided in Reference 1 is not met the following actions will be pe rf o rmeo.
PIior to power operation following zero power physics testing, the on-site review committee will verify that adequate shutdown margin exists between the measured shutdown capability and the shutdown requirement for that cycle employing the following formula:
(0.9 Mos} (PT)
WSR - R MSC (% a p) rRS
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Measured shutdown capability; where:
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Measured N rod worth employing the Mg5 2
rod swap technique; Predicted N rod worth for the rou PRS
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swap configuration, Preoicted N rod worth in the all Py
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rods in (ARI) configuration; Worth of most reactive stuck rod; and WSR
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Reactivity requirement for shutdown R
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l purposes.
Resolution of any anomaly related to meeting a safety limit l
will be handled and reported, if applicable, per Technical specification requirements.
1 Prior to sustained power operation above 75% of rated power, the on-site review committee will investigate the composite plant startup data and the applicability of reload safety analyses.
The ultimate resolution of the violation of the rod exchange safety criterion will be documentea and the resident NRC inspector will be i
informed of the violation and resolution thereof.
l By Reference 2, Westinghouse incorporated the rud-exchange documents originally referenced by Commonwealth Edison into a i
topical report titled " Rod Bank North Measurements Utilizing Bank l
Exchange", WCAP-9863 (Proprietary version) and WCAP-9864 (Non-i I
proprietary version).
By Reference 3, Westinghouse provided information to be incorporated into these documents on actions to be taken upon failure to meet the acceptance criterion ahich are in conceptual agreement with the actions provided herein.
Tne design and safety criteria provided in tne Reference 1 submittal ano the aforementioned remedial actions conform to the criteria provided in WCAP-9863 ano WCAP-9864.
We unoerstand that the NRC review of our request aill proceed from your review of tnose topicals.
Please address any questions that you may have concerning this matter to tnis office.
One (1) signed original and thirty-nine (39) copies of this letter are provided for your use.
Very truly yours, M/Yo hj= ^ -
T.
R.
Tramm Nuclear Licensing Administrator Pressurized Water Reactors cc: Resident Office-Zion 11888 l