ML18046B095

Safety Evaluation Supporting Revised Operating Allowance for Steam Generator B.Evaluation Based on Findings of Sept- Oct 1981 Insp of Eddy Current Testing,Data Evaluation & Tube Plugging

ML18046B095
Person / Time
Site:	Palisades
Issue date:	11/05/1981
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML18046B094	List: ML18046B093 ML18046B095
References
NUDOCS 8111250296
Download: ML18046B095 (2)

Text

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, A UNITEDSTA1ES

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• • . WJUCLEAR REGULATORY COMM IS~

WASHINGTON; D. C. 20555 PALISADES PLANT SEPTEMBER-OCTOBER 1981 STEAM GENERATOR INSPECTION SAFETY EVALUATION REPORT

. DOCKET NO *. 50~2~5

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• _ By* letter dated October 16, 1981, Consumer Power:- Company (the licensee) submitted _the results of September-October 1981 steam generator* inspection

~:.~~~::at: the ~Palisades. Plant: <.Th.e Se~pfe.inoer-:.October-1981 inspection. followed

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seventeen C17) months of ope~ation *conducted at approximately full power

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since the previous inspection.

Based upon September-October 1?81 inspection results, the licensee has requested approval of a new operating allowance

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_(for future degr~dation) ;n accordance with Section 4.14 of the Palfsades Plant Technfcal *specificatio~;

• DiSClJSSION Section 4.14 of the Palisades Plant Te~hnical Specification requires establishing of tube plugging criteria based on the operating allowances.

\\.Jhe.n an inspection reveals that the tube degradation plus an NRC approved appropriate operating allowance is greater than the maximum allowable degrad~~ion specified in Table 4.14~2, the tube will be declared to be

• defe'ctive and tube plugging or sleeving will be performed *. This operating allowance, however, is related to the ~ean wastage increase (corrosion.

rate) over the period since the previous steam*generator inspection. If the mean w~stage increase is less than +1 percent (essentially no wastage),

the operating allowances listed in Table 4.14.1 are applicable.

If the

~ean wastage increase is greater than or equal to +1 percent, the licensee must submit new operating allowances to NRC for approval prior to return to operatiori~

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()I EVAL!JATION.

We have.reviewed the licensee's submittal dated October 16, 1981 regarding

~-the data evaluation and tube plugging p~rformed as a res~lt ofcihe-steam

- generator inspection which*::took place from Septemb.er 18 to October 7, 1981 *

. We find.th~ method ~hich the licensee used to ~stimate th~ c6~~osion-~ate

-for beth f.. and B Steam Generators acceptable. *The licensee estimated less -

~-~*tu~n +1 j:>ercent corrosion *.growth for the A Steam Generator. Tubing and 3.09

_ percent ccirros_ion;.growth for the B Steam Generator Tubipg._. ~~.i.nce B. :::: -<<~

-. Ste.am. Gene t.~t o'r. does'.. indicate an appa ren't'~-me-an-c~astage'- i;, c'~e:~~-~~~ of greater

• iha~ +1 pe~te~~, a riew operating allowan~e ii.re~u{red.

We concur with*

the lice~see that.op~rating allowance stipul~ted in Table 4.~4-1 ~e

-- i~creased :from,,6 percent to 10 percent to-compensate for *th~_,4***percent mean wastage increase of B Steam Generator. This change is c6nsistenf with the

~Regulatory_ Guide 1.121 and will pr-;vi de addition al assurance that Pali sades Plant is safe to return to power operation without adverse effect to the health and safety of the public.

Dated:

November 5, 1981