IR 05000321/1988034

Ack Receipt of Informing NRC of Steps Taken to Correct Violations Noted in Insp Repts 50-321/88-34 & 50-366/88-34.Both Active & Passive Electrical Failures to Be Considered for short-term Action for Reasons Stated

ML20235Y299
Person / Time
Site:	Hatch
Issue date:	03/01/1989
From:	Reyes L NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
To:	Hairston W GEORGIA POWER CO.
References
NUDOCS 8903140044
Download: ML20235Y299 (5)

Text

.

. .

<

c- , l '

.[c ff' yf 5

,

.

l MAR 0 i 1989  ;

,

Docket Nos.. 50-321, 50-366-License Nos. DPR-57, NPF-5 j

. I

'

. Georgia Power. Compan : ATTN: Mr. W. G. Hairston, III-Senior Vice President -

Nuclear Operations

P. 0.' Box 1295 Birmingham, AL 35201- ,

J Gentlemen:

SUBJECT:- NRC INSPECTION REPORT NOS. 50-321/88-34 AND 50-366/88-34- 'l Thank you for your response of January 13, 1989, to our Notice of Violation q-issued on December 14, 1988, concerning activities conducted at your Hatch j facility.: We have evaluated your response and found that it meets th '

-requirements of.10.CFR 2.20 In' your response, you'admitte'd both violations but presented several mitigating -

circumstances for violation A, which concerned the inadequate' evaluation of an a'utomatic depressurization system (ADS) design deficiency. Although violation

. A was admitted, you concluded that the NRC had not specifically backfit the design basis requirement to consider passive electrical failures, that the operability of the ADS system was never in question,Jand that the action statement for Unit 2 Technical Specification 3.5.2.b for having ADS inoperable was.not required to be entere After careful review of your response, we have concluded, for the . reasons presented in the enclosure to. this letter, that both active and passive electrical failures are to be considered for short-term action, that the operability of the ADS system was in question, and that the action statement of Unit 2 Technical Specification 3.5.2.b for having ADS inoperable was required to be entere We will examine the implementation of your corrective actions during future inspection We-appreciate your cooperation in this matte / Sincerel t

'

, s903 [C p PDR Luis A. Reyes, Director a x N Division of Reactor Projects Enclosure:

Evaluations and Conclusions cc w/ encl: (See page 2) [ {

l

- _ - _ _ _ - _ - _ _ _ _ _ - - N #l _\

_ - - _ _ - - __ _

. . .

-

,

.

'

[

.

ihl ,

lb Geo.rgia Power Company' -2 ,

.

cc w/ enc 1:

.R. P. Mcdonald, Executive Vice:

_

President,LNuclear Operations

J. T.iBeckham, Vice President, Plant' Hatch

H. C; Nix, General: Manager;-Plant _ Hatch 0.~M.:Fraser, Site Quality Assurance Manager

.L. T. Gucwa, Manager,1 Nuclear Engineering and Licensing,- ,

LPlant Hatch S. B. Tipps, Manager. of Nuclear -

. Safety and_ Compliance-

~

State of Georgia =

bec w/ enc 1:

L. P. Crock'er,,NRR M..V..Sinkule, RII-

, NRC. Resident' Inspector l DRS Technical Assistant Document-Control Desk-b e ,,

l L

i _

y'

RII Rll R11 g7 v46 {1 LTrocine MSinkule AHerdt 2/r/89 2/73 /89 2/j3/89 Y #8"

@Qb'/87 l

l:

E_ _ _ _ _ _ _ _ _ _ - _ _ _ _ _ _ _ _

_ _ _ _ _ _ _ _ _ _ _ _

,

w

. .

,

I ENCLOSURE l

EVALUATIONS AND CONCLUSIONS Introduction On October 26, 1988, Georgia Power Company (GPC) was orally granted temporary relief from compliance with Unit 2 Technical Specification limiting condition for operation 3.5.2, action statement b, which requires the unit to be in at least HOT SHUTDOWN within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and the steam dome pressure to be less than or equal to 150 psig within the next 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> if two or more of the required automatic depressurization system (ADS) valves are inoperable. It had previously been determined that the failure of station battery "A" coincident with a certain sized loss-of-coolant accident (LOCA) would prevent the automatic actuation of ADS. The decision to grant discretionary enforcement action was based on the following: (1) the low probability of the failure mode coincident with a pipe break of a critical size during the time frame required to modify the design, (2) the fact that 'the high pressure coolant injection system would still be available to mitigate a postulated LOCA for small or intermediate break sizes, (3) the fact that manual actuation of ADS could still be accomplished within a reasonable time frame, and (4) the fact that the shift supervisors and plant operators had been briefed on the design deficiency and the potential of the single failure to disable AD The discretionary enforcement action allowed GPC to continue operation of Hatch Unit 2 until a design change could be implemented to correct a design deficiency in the ADS power supply circuitr During a second conference call on October 27, 1988, GPC committed to shutdown Unit 2 and implement the proposed modifications prior to January 1,1989. The licensee also committed to perform the proposed modifications on Unit 1 prior to restarting the reactor at the end of the ongoing refueling outage, which at the time was scheduled for December 4, 198 The proposed modifications were implemented within the time constraints granted by the discretionary enforcement actio Two Severity Level IV violations involving the inadequate evaluation of an ADS design deficiency and the failure to follow a test procedure which resulted in inadvertent isolation of shutdown cooling were issued on December 14, 1988. An additional violation concerning the inadequate control of the design of the Analog Transmitter Trip System modifications which resulted in ADS being vulnerable to a single failure was considered to be a licensee-identified violation and was not cited. In a letter dated January 13, 1989, GPC admitted the violations but presented several mitigating circumstances for violation A, which involved the inadequate evaluation of an ADS design deficiency. A restatement of violation A, summary of the licensee's assertions, and the NRC's evaluations and conclusions are presented below:

-_ - - - - - - - - - l

_ .__ _ _ - - _ _ _ _ . _ . _ _ _ - _ - _ . ____ . _ _ . ______ __

_ _ - _ _ _ - _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ . _ - _ _ _ _ _ - _ _ _ _ _ _ _ _ _ _ _ -

Q

-

.. .

,

-

s Enclosure 2 Restatement of Violation A 10 CFR Part 50, Appendix B, Criterion XVI, " Corrective Action," requires that measures be established to assure that conditions adverse to quality, such as deficiencies, are promptly identified and correcte Contrary to the above, appropriate initial corrective action was not taken when it became known that the Automatic Depressurization System (ADS) was designed such that a single failure could result in a loss of automatic system operatio The reviews of this matter during the period October 25-26, 1988, failed to conclude that the vulnerability of ADS to- the failure of the "A" station batteries was contrary to 10 CFR Part 50, Appendix A, General Design Criterion 35, and required that ADS be declared inoperable. Consequently, the Action Statement of Unit 2 Technical Specification 3.5.2.b for having ADS inoperable was not entered. The licensee became aware that ADS should have been considered inoperable when so advised by the NRC on October 26, 198 Unit I was in the REFUEL mode and Unit 2 was operating at rated power during this time perio This is a Severity Level'IV violation (Supplement I). (Unit 2 only)

Summary of Licensee Assertions GPC admitted violation A but presented several mitigating circumstance In its response, the licensee referenced General Electric Topical Report NED0-20566, the NRC Safety Evaluation Report, and Appendix K to 10 CFR Part 50, and contended that the battery failure was not a required design basis for BWR plants of the same vintage as Hatch, that in 1979 the NRC was agreeable to the use of the original design basis for emergency core cooling system evaluations, and that in 1980 the NRC reportedly gave verbal concurrence to the proposal that passive electrical failures need not be considered. GPC also referenced the 1984 General Electric SAFER Report and concluded that the NRC had not specifically backfdt the design basis . requirement to consider passive electrical failure Additionally, the licensee asserted that a passive electrical failure should not be considered for short-term action, that the capability of the ADS system to perform its safety function was not impaired, and that the operability of the ADS system was never in question. Therefore, GPC contended that the action statement of Unit 2 Technical Specification 3.5.2.b for having ADS inoperable was not required to be entered. GPC also stated that despite that fact that the licensing basis for Hatch does not require consideration of passive failures, the intent of 'the General Electric ADS design was that the system be single failure proof, including a passive failure of a station batter Additionally, ' GPC admitted that the configuration of the electrical system for ADS was found to be vulnerable to the failure of station battery "A" and that this was considered to be a design deficiency.

- - _ _ _ _ _ _ _ _ _ _ _ _ _

. _ _ _ _ _ _ _ _ _ _ _ _ - _ _ _ - - _ - _ _ _ _ _ _ - _ _ _ _ _

'

.

. .

,

.

Enclosure 3 NRC Evaluation While the NRC staff agrees that both Appendix K of 10 CFR Part 50 and the 1984 General Electric SAFER Report refer to consideration of active failures for short-term action and to consideration of both active and passive failures for long-term action, these reviews pertained to regarded thermal hydraulic failures and were not intended to include electrical failures. Additionally, when Appendix A to 10 CFR Part 50 was established, it very explicitly required consideration of both active and passive electrical failures for short-term actio NRC Conclusion ]

The NRC staff has carefully reviewed the licensee's response and has concluded for the reasons presented above that both active and passive electrical failures are to be considered for short-term action, that the operability of the ADS system was in question, and that the action statement of Technical Specification 3.5.2.b for having ADS inoperable was required to be entered.

l L_----_---_--------_-------- _- - - - - - _ - - - __ __ _.