ML20141M850

Responds to NRC Re Violations Noted in Special Team Insp Rept 50-304/85-06.Corrective Actions: in-containment Equipment in Environ Qualification Program Will Be Identified & Temp Profile Evaluated

ML20141M850
Person / Time
Site:	Zion File:ZionSolutions icon.png
Issue date:	12/27/1985
From:	Farrar D COMMONWEALTH EDISON CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML20141M849	List: IR 05000304/1985006 ML20141M850
References
0946K, 946K, IEB-79-01B, IEB-79-1B, NUDOCS 8602280423
Download: ML20141M850 (4)

Text

. Commonwealth Edison One First Nation:t Prpa Chiergo. libnors Address Reply to Post Othee Box 767 Chicago, lihnois 60690 December 27, 1985 Mr. James G. Keppler Regional Administrator U.S. Nuclear Regulatory Comission Region III 799 Roosevelt Road Glen Ellyn IL 60137

Subject:

Zion Nuclear Power Station Unit 2 Inspection Report No. 50-304/85-006 NRC Docket No 50-304 References (a): April 15, 1985 letter from G. G. Zech to Cordell Reed (b): August 21, 1985 letter from J. J. Harrison to Cordell Reed (c): September 20, 1985 letter from L. O. Delceorge to J. G. Keppler (d): November 21, 1984 letter from S. A. Varga to D. L. Farrar (e): April 10, 1984 letter from F. C. Lentine to H. R. Denton

Dear Mr. Keppler:

Reference (a) transmitted the report of a special team inspection conducted by Mr. G. T. Hubbard and other NRC representatives on January 14-18, 1985, at the of fices of Cunmonwealth Edison Company and Sargent and Lundy in Chicago, Illinois, and at Zion Station Unit 2, Zion, Illinois, of activities authorized by NRC License No. DPR-48.

This report identified four items as Potential Enforcement /

Unresolved Items and referred them to the NRC Region III office for further action. Reference (b) classified two of these four items as examples of a violation of 10 CFR 50.49 and requested that Commonwealth Edison provide additional information concerning the remaining two. These two remaining issues, the removal of four TER items and the use of LOCA environmental parameters for qualification, are the subject of this letter.

9602290423 960224 PDR ADOCK 03000304 PDR 0 DEC 311985

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December 27, 1985 J. G. Keppler Reference (c) provided Commonwealth Edison Company's position on these two issues. Subsequent discussions with Region III personnel have indicated the need for further clarification. The two issues will be discussed separately below.

LOCA vs MSLB Environmental Profiles Attachment 4 of reference (c) stated that Commonwealth Edison Company has been utilizing the LOCA environmental profile for in-containment equipment qualification since 1979. Commonwealth Edison believed in 1983, and continues to believe, that 10 CFR 50.49 was never intended to require any reanalysis of Zion's design basis accidents. Thus, the imposition of a requirement to perform additional analyses is unwarranted.

In addition, the transient, sharply-peaked temperature profile that is characteristic of the large dry MSLB containment response would probably produce a less severe qualification profile than is presently utilized.

This would be due to the shorter time duration required at elevated temperatures. Thus, while the MSLB profile may have a higher peak temperature, it's short duration would probably result in lower equipment temperatures than the 271*F utilized for Zion's equipment qualification program.

It is our understanding that a demonstration of this phenomenon would be useful in resolving this issue and in the closure of the unresolved item.

Thus, Commonwealth Edison proposes the following:

1. The in-containment equipment currently in Zion's EQ program will be identified.

2. Commonwealth Edison will evaluate the temperature profile for Zion's design basis MSLB.

3. The replacement equipment with the most limiting heat transfer l

characteristics (e.g. surface / volume ratio, heat capacity) will be

' calculationally subjected to the MSLB profile discussed above.

f 4. The resulting equipment temperatures will be compared to the

! existing qualification profile of 271*F for over two hours.

5. A report describing this analysis and its results will be supplied to the NRC.

]

l If this methodology is a acceptable mechanism to resolve this

• - issue, Commonwealth Edison will supply a schedule for the completion of this work by February 28, 1986.

December 27, 1985 J. G. Keppler REMOVAL OF TER ITEMS Attachment 3 of reference (c) stated that Commonwealth Edison Company has presented the deletion of the TER items to the NRC and it has been formally accepted by NRR. The acceptance was contained in the SERs for Zion's EQ program (reference (d)) and was clearly stated. It discussed the relationship of the Reg. Guide 1.97 review to the EQ rule and ackr.owledged the fact that the 1.97 review was incomplete. In addition, the deletion of the TER items was discussed in reference (e), which was also discussed in the approval.

Commonwealth Edison has been acting in accordance with the approval obtained in reference (d). Our communication regarding this matter and the NRC's approval appears equally clear. Thus, the validity of the removal of these items from Zion's EQ program should not be an iseue at this time.

However, reference (b) requested that Commonwealth Edison provide a technical justification for the removal of these four items. Thus, a short discussion of why Commonwealth Edison has no technical reservations concerning these four items may be useful in resolving this issue.

These instruments (RVLIS, containment pressure, cont. sump level, and cont, hydrogen level) were originally included in Commonwealth Edison's EQ program in response to the explicit guidance of KRC IE Bullatin 79-01B, Supplement 3, Item 2. Subsequently, a detailed review of the Zion's overall design and operation was conducted to identify equipment covered by 10 CFR 50.49(b). This review is outlined below.

The review considered six essential safety functions. These functions were as follows:

1. Emergency reactor shutdown

2. Containment isolation

3. Reactor core cooling

4. Containment heat removal

5. Core residual heat removal.

6. Radioactive material release prevention.

Plant systems were reviewed to identify those systems required for performing the essential safety functions. Piping and instrumentation diagrams for each cf the systems identified were reviewed to identify system components essential to the performance of the system's safety function or whose failure would affect performance of the system's safety function. A review of the Zion FSAR, Emergency Operating Procedures (EOPs). Technical Specifications and a review by station operating personnel were conducted to ensure the completeness of the equipment list.

J. G. Keppler December 27, 1985 Specifically, the plant emergency procedures were reviewed to identify all devices and display instruments required to be used by the operator. The instruments which would be exposed to a harsh environment following a design basis accident were then included as part of the 10 CFR 50.49 equipment list, as required by Paragraph (b).

It is extremely important to note that the four instruments in question were not identified during this review process. Thus, the devices were not pertinent to the performance of the six functions discussed above.

However, the EQ status of these items continued to be monitored upon issuance of 10 CFR 50.49 in early 1983 because of some confusion about the relationship between IEB 79-01B, Supplement 3, 10 CFR 50.49, and the EQ work performed prior to 1983.

Thus, commonwealth Edison Company realized in late 1983 that the treatment of potential Reg. Guide 1.97 instrumentation was an issue that should be dealt with separately. The removal of these instruments from Zion's EQ program was of no technical concern, because they had been shown to be unrelated to the six safety functions and had not been identified as part of the 10 CFR 50.49 equipment list. Their presence was a historical throwback to IEB 79-01B. Thus, the Company's intention to delete these items pending further review was clearly stated at the January 25-26, 1984 meeting, in writing in the cover letter of reference (e), and again in the meeting material attached to reference (e). Thus when reference (d) was received, the clarity of our previous communications appeared to be reflected in the SER's approval.

These issues and the responses contained in this letter have been discussed with Mr. Uldis Potapovs of NRC-I&E, If any further questions arise concerning this matter, please direct them to Commonwealth Edison's Nuclear Licensing Department.

Very truly yours,

. ~

D. L. Farrar Director of Nuclear Licensing im cc: J. Norris - NRR Zion Resident Inspector 0946K t