ML20135G114

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Provides Addl Info Re Item 1.1 of Generic Ltr 83-28 Concerning post-trip Reviews,Per 850729 Request.Initial post-trip Investigation Is Responsibility of Duty Technical Advisor & Duty Shift Superintendent
ML20135G114
Person / Time
Site: Point Beach  NextEra Energy icon.png
Issue date: 09/10/1985
From: Fay C
WISCONSIN ELECTRIC POWER CO.
To: Butcher E, Harold Denton
Office of Nuclear Reactor Regulation
References
CON-NRC-85-101 GL-83-28, TAC-52786, TAC-52787, VPNPD-85-309, NUDOCS 8509180173
Download: ML20135G114 (3)


Text

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%0SCORSin Electnc roara courasr 231 W. MICHIGAN, P.O. BOX 2046. MILWAUKEE, WI 53201 September 10, 1985 VPNPD-85-309 NRC-85-101 Mr. H. R. Denton, Director Office of Nuclear Reactor Regulation U. S.~ NUCLEAR REGULATORY COMMISSION Washington, D. C. 20555 Attention: Mr. Edward Butcher, Acting Chief Operator Reactors, Branch No. 3 Gentlemen:

DOCKETS 50-266 AND 50-301 RESPONSE TO SAFETY EVALUATION FOR GENERIC LETTER 83-28, ITEM 1.1 (POST-TRIP REVIEW)

POINT BEACH NUCLEAR PLANT, UNITS 1 AND 2 Your letter dated July 29, 1985, which we received on August 5, 1985, provided a safety evaluation of our post-trip review proced're. That procedure had been provided in our response to Itet 1.1 (Post-Trip Review) of Generic Letter 83-28. Included with your July 29 letter was a request for additional information regarding these post-trip reviews. The information requested and our responses are provided below.

1. The method and criteria for comparing the event with known or expected plant behavior.

PBNP 3.4.10, " Post-Trip Review", Section 4.3, provides for a post-trip investigation. The initial post-trip investi-gation is the responsibility of the Duty Technical Advisor (DTA) and the Duty Shift Superintendent (DSS). A portion of this investigation is the gathering of all the pertinent information concerning alarms, trip actuations, isolations, and the plant computer printout. This transient information is reviewed to determine if the system response was appropriate with respect to normal system function and the reviewer's understanding of the plant response. This reconstruction is 8509180173 850910 PDR ADOCK 05000266 j(O dII P PDR gj

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Mr. H. R. Denton September 10, 1985 Page 2 also compared with procedural actions to determine the effect of procedural performance on plant response. A comparison to previous transients is also done if data are available. The post-trip investigation is documented in Section 4.9 of the emergency checklist 5, " Post-Trip Reviews".

We have not yet had a "FSAR transient" and so have not had the need to use the FSAR data in a post-trip review.

Because the FSAR evaluations generally presume a worst-case scenario, the reviewer (s) must be cautious in the critique /

comparison to not use the data indiscriminately. This caution was noted by INPO in their " Good Practice for Post-Trip Review" (OP.211). If we experience a transient analyzed in the FSAR, we would use applicable FSAR curves and data.

2. The development of a systematic safety assessment program to assess unplanned reactor trips.

A systematic safety assessment is also accomplished in Section 4.3 of PBNP 3.4.10, " Post-Trip Review". Investi-gations of the trip cause and the plant response are conducted under the two following criteria:

a. Have all safety-related and other important equipment involved in the trip operated as anticipated?
b. Has the trip / transient caused any detrimental ef fects upon plant equipment?

In this assessment the DTA and DSS look beyond obvious indications to diagnose the trip cause and plant response.

This review includes information which may indicate events such as, but not_ limited to, the following:

a. Abnormal indications or degraded equipment performance.
b. Events occurring out of ncrmal or anticipated requence or outside of normal parameter bounds.
c. Failed or degraded equipment response to control signals.
d. Unusual chemistry results or radiation readings.
e. Unanticipated alarms.

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J Mr. H. R. Denton September 10, 1985 Page 3 This assessment includes the comparison of minimum and maximum values of selected parameters to applicable specifications. The safety assessment is documented in Sections 4.6, 4.7, and 4.8 of emergency checklist 5,

" Post-Trip Review".

I This interpretation of a systematic safety assessment program is consistent with our understanding of Item 7 in Section 1.1 of Generic Letter 83-28 and INPO " Good Practice for Post-Trip Review" (OP.211), Section 2.0, Scope.

We trust the above discussion addresses the staff's recom-mendations and responds to the items noted in your safety evaluation. Should you have any questions regarding our procedure for post-trip reviews, please let me know.

Very truly yours,

- (-

i?Ch},

C. W. Fay Vice President Nuclear Power Copy to NRC Resident Inspector

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