ML20205E806

Informs of Performance Appraisal Team Insp Results,Including Concerns Associated W/Emergency Feedwater (EFW) Power Cable Equipment Qualification & Manually Operated EFW Flow Control Block Valves

ML20205E806
Person / Time
Site:	Three Mile Island, 05000000
Issue date:	04/25/1986
From:	Stolz J NRC
To:	Harold Denton NRC
Shared Package
ML20205E603	List: ML20205E600 ML20205E655 ML20205E673 ML20205E679 ML20205E693 ML20205E705 ML20205E726 ML20205E739 ML20205E758 ML20205E781 ML20205E789 ML20205E795 ML20205E806 ML20205H450
References
FOIA-86-293 NUDOCS 8608180489
Download: ML20205E806 (2)

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April 25,1986 k . . . . . ,o/

l NOTE T0: Harold Denton .

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FROM: John Stolz

SUBJECT:

PAT INSPECTION RESULTS AT TMI-1 The PAT formal report on TMI-1 is due to be published this month. The PM talked to each member of the team and was present for the internal exit meeting conducted before the final exit with the licensee. The PM left the meeting with the impression that the PAT liked many of the things GPU was doing at TMI-1. However, the PAT exit focused on only the negative comments.

The PAT reviewed in detail the installed EFW system and supporting systems.

Two of the PAT findings are of significance in the near time frame:

(1) equipment qualification questions concerning an EFW system power cable, and (2) a change in mode of operation for the EFW block valves. A third conc'ern associated with the two hour back-up air supply, is a long term concern affecting the modified EFW system planned for completion by the next refueling outage. The present EFW flow control valves fail in the open position on loss of air which is what is desired. Although the EFW system was reviewed in detail in the TMI-1 restart proceedings, the 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> back-up air supply was not a specific contention in the hearing. Each area will be discussed in turn.

(1) EFW Power Cable EQ The PAT found a power cable used in the EFW system with insufficient documentation to support its environmental qualification. The original PAT finding was resolved and the power cable involved was found to be environmentally qualified. However, followup actions raised questions concerning the generic qualification of items such as cables, terminal blocks, splices and electrical seals. The licensee has resolved NRC concerns and I will document the results of a series of calls and a site meeting in a letter to be sent to Region I shortly. While conducting this review, the licensee discovered unqualified power cables in the containment air coolers. Startup is l delayed while these cables are being replaced. A separate highlight was prepared covering the details of this issue.

(2) EFW Flow Control Block Valves l

The licensee is changing the EFW flow control block valves from being remotely operated, as evaluated in the staffs review of the system in NUREG-0680, to manually operated only valves. This issue affects the upgraded EFW design to be implemented at the next refueling outage for TMI-1. We will be reviewing this design change as part of our on-going review of the up-graded EFW design.

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( The PAT understood that the licensee was planning to make the change under 50.59. We informed the licensee in December 1985 that the staff nedded to review the change, since reference to the remotely operated valves design was part of the TMI-1 hearing record.

(3) Instrument Air Supply System stems: (a) normal The instrument instrument air supnon-seismically air supply ly consists of the following( back-up instrument air supply (non-seismically qualified), (c) two qualified),

hour back-up instrument air supply (seismically qualified and supposed to be single failure proof), and (d) a back-up portable bottle air supply continuously attached to the system. The two hour back-up instrument air supply is not single failure proof as described in the FSAR. 'The PAT found one instance where a seismic event coupled with a single failure could result in loss of all instrument air.

Currently all valves of concern would fail in a safe condition (i.e. EFW flow control valves fail open and the turbine throttle valve fails open for the turbine driven EFW pump). However, after the next refueling outage, EFW flow control valves will fail shut. Based on the PAT identification of the

instrument air supply system deficiency, the licensee issued an LER and is currently seeking a solution. Tentatively, the licensee can shut two normally open valves and perhaps solve the problem. The Resident, Project Manager, and a reviewer (Jared Wermiel) have reviewed the tentative plan and it appears to be acceptable if the valves are seismically qualified. The PM will review with the resident, the licensee's proposed resolution and determine if further corrective action is necessary. This issue only affects the upgraded EFW design.

W bF. Stolz cc: . ,

JJ F. Miraglia

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