ML17286B153

Proposed Tech Spec Table 3.3.6-1.4.a Re Rod Block intermediate-range Monitor Not Full in Signal

ML17286B153
Person / Time
Site:	Columbia
Issue date:	11/18/1991
From:	WASHINGTON PUBLIC POWER SUPPLY SYSTEM
To:
Shared Package
ML17286B152	List: ML17286B151 ML17286B153
References
NUDOCS 9111260155
Download: ML17286B153 (8)

Text

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TABLE 3. 3. 6-1

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tlO p~, Cj) CAtffROL ROD DI.OCK IHSTRUHEHTATIOH 0Ql

'KQl HI HI HUH APPLICABLE

'O% OPERABLE CIIAHHELS OPERATIONAL Vl)

'fRIP FUHCT10tl

')

. PER TRIP f'UNCTION COtlDITIONS ACTION O)

. VO) ao)m <- l. RAD BI.OCK HOHITOR(a)

Z'0 a. Upsca1 e 2 $

)II 60 I). ti I nope ra ve .2 1)k 60

c. Downscale 2 1 IIC 60

2. APIIH

a. F'low Biased tleut.ron Flux Upscale A 1 61 I). Inoperative Pg@ I, 2, 5 Gl c.

d.

Downscale tteut.ron Flux - Upscale, Star tup Py 1 21 5

~ 61 61

3. SAUIICE RAHBE tlAHITARS

a. Detector nut full in(b) 61 61 t). Upscal e(c) 3 2 61 61

c. 'noperaLive(c) 3 61 2 61

)I. Downscale(d) .3 Gl 2 61 ItlTERtlFOIATE RAtlGE tR)tlITORS

a. Detector not. full in 2 61 I). Upscale 2. 61

c. Inoperat.ive 2. 61

)I. Downscale(e) 2 61

5. SCRAH DISCIIARCE VOLUIIE

a. Mater Level-IliDh 1 2 5'I* 62 I). Scram Trip Bypass GAL 62 G. REACTOR CADI.Atff SYSTEtt ltFCIRCULATIAtl FI.AM

a. Upscal e 62 I). Inupera t i ve 62

c. Ct)mt)a ra to). 62 Ioj,

'age 2 RE(VEST FOR AMEND. TO TS TABLE 3.3.6-1.4.a CONTROL t

ROD BLOCK INTERMEDIATE RANGE MONITOR NOT FULL IN SIGNAL A recent review of the instrument design and technical specification descriptions recognized that the technical specification implied, by footnote "(e)", that the rod block signal was bypassed (not effective) when the IRHs were in range 1 of the 1 through 10 instrument switch settings (range 1 corresponding to the lowest power setting). This appears to have been an oversight in the original preparation of the WNP-2 Technical Specifications. In fact, the rod block bypass inferred by Note "e" was never part of the original design, was never considered and does not exist.

Bypassing the IRH control rod block signal in range 1 is nonconservative. In range 1 overlap with the Startup Range Monitors (SRH) is confirmed and proves that the IRH detectors are functioning correctly. Should an IRH be out of position overlap and functionality of the IRH could be confirmed when in fact the IRH has malfunctioned. This would invalidate any protective action claimed for that IRH. Hence, an accident analysis which took credit for IRM operation would be invalid. As a result a "bypass" in range 1 would cause WNP-2 to be outside the design bases. Accordingly, a Technical Specification change is necessary.

Although the WNP-2 Technical Specifications imply a bypass in range 1, review of plant surveillance procedures confirms that the design (no bypass in range 1) is being proven operable on the appropriate schedule. The Technical Specification Channel Functional Test required by Table 4.3.6-1 is performed in range 1.

Further, design documents confirm that the Range Selector Switch is not physically in the detector not full in" circuitry. In other words the "detector not full in" circuitry and associated signals are independent of the Range Selector Switch. A bypass using the switch is not possible in the present design. As such the proposed change is appropriate.

The Supply System has evaluated this amendment request per 10 CFR 50.92 and determined that it does not represent a significant hazards consideration because it does not:

1) Involve a significant increase in the probability or consequences of an accident previously evaluated because the change corrects the Technical Specifications to reflect the original, correct, and more conservative design. In this instance there is no increase in the probability or consequences of an accident previously evaluated because the Technical Specifications are being changed to show the original intent of the design and the original support provided by the IRH system as evaluated in the accident analyses. Hence, the accident analyses remains unchanged.

2) Create the possibility of a new or different kind of accident from any accident previously evaluated because the IRH function and reliability are not affected by this change. No new modes of plant operation are introduced with this change. Hence, no new or different kind of accident is credible.

3) Involve a significant reduction in a margin of safety because as stated above no change to the original design or accident analysis is affected or reduced by this change. Therefore, there is no impact to a margin of safety with this change.

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Page 3 RE(UEST FOR AMEND. TO TS TABLE 3.3.6-1.4.a CONTROL ROD BLOCK INTERMEDIATE RANGE MONITOR NOT FULL IN SIGNAL i

As discussed above, the Supply System considers that this change does not involve a significant hazards consideration, nor is there a potential for significant change in the types or significant increase in the amount of any effluents that may be released offsite, nor does it involve a significant increase in individual or cumulative occupational radiation exposure. Accordingly, the proposed change meets the eligibility criteria for categorical exclusion'set forth in 10 CFR 51.22(C)(9) and therefore, per 10 CFR 51.22(b), an environmental assessment of the change is not required.

This Technical Specification change has been reviewed and approved by the WNP-2 Plant Operations Committee (POC) and the Supply System Corporate Nuclear Safety Review Board (CNSRB). In accordance with 10 CFR 50.91, the State of Washington has been provided a copy of this letter.

Very truly yours, G. C. Sorensen, Manager Regulatory Programs PLP/bk Attachments cc: RG Waldo - EFSEC JB Hartin - NRC RV NS Reynolds - Winston 8 Strawn PL Eng - NRC DL Williams - BPA/399 NRC Site Inspector - 901A

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Request for Amendment - Control Rod Block Intermediate Range Monitor Not STATE OF WASHINGTON )

Subject:

Full in Signal COUNTY OF BENTON I, G. C. SORENSEN, being 'duly sworn, subscribe to and say that I am the Manager, Regulatory Programs, for the WASHINGTON PUBLIC POWER SUPPLY SYSTEM, the applicant herein; that I have full authority to execute this oath; that I have reviewed the foregoing; and that to the best of my knowledge, information, and belief the statements made in it are true.

DATE: , 1991

. C. Sore sen, Manager Regulatory Programs On this date personally appeared before me G. C. SORENSEN, to me known to be the individual who executed the foregoing instrument, and acknowledged that he signed the same as his free act and deed for the uses and purposes herein mentioned.

GtvB d yI. d d Mii lM dy f~V7 1991.

Notary Public in and for the STATE OF WASHINGTON My Commission Expires A ri12 199

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