ML19329A572
| ML19329A572 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 02/26/1971 |
| From: | Schwencer A US ATOMIC ENERGY COMMISSION (AEC) |
| To: | Deyoung R US ATOMIC ENERGY COMMISSION (AEC) |
| References | |
| NUDOCS 8001070569 | |
| Download: ML19329A572 (5) | |
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UNITED STATES
- N ATOMIC ENERGY COMMISSION l.~ y j.
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WASHIN GTON, D.C.
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u February 26, 1971 Richard C. DeYoung, Assistant Director for PWRs, DRL TilRU :
Charles G. Long, Chief, PWR Project Branch No. 2, DRL
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SITE VISIT TO DUKE POWER COMPANY'S OCONEE NUCLEAR STATION, DOCKET No. 50-269 Summary A site visit to examine the installed Oconee Nuclear S'.ation electrical and instrumentation systems related to safuty was made February 11 and 12, 1971. An attendance list la enclosed.
It had been rescheduled f rom last November due to delays at the site.
Details of the findings have been prepared by the electri-l cal and instrumentation reviewer, Olan Parr.
In general, however, there were only a few areas that were considered to warrant corrective action by the applicant. To correct these, the applicant has agreed to:
1.
Provide adequate ventilation to both battery spaces in the hydro station battery room.
2.
Keep the switchgear house locked.
3.
Perform periodic inspection on the redundant batteries and auctioneering diodes associated with operation of the 230 KV suitchyard breahars.
4.
Perf orm an evaluation of all safety-related functional devices in the control room to determine if any more safety-related devices have been overlooked (not been properly identified and treated as safety-related items),
to take such corrective action as may be warranted and to let DRL and the CompF ance Inspector know the results of the evaluation and sue equent corrective actions taken.
5.
Block off a temporary steam line upstream from the Unit 1 4160V ESF switchgear.
In addition to the above, although not required to meet our single failure criterion, the applicant informally agreed to
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investigate the feasibility of rerouting an instrument air line and a floor drain line wh.ich pass through one of the two redundant control battery rooms associated with operation of Unit 1.
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' R. C. DeYoung OTilER IllNS OF INTEREST Estimated Fuel Loading and Commercial Operation Dates The applicant now expects to be ready to load fuel in July 1971 a
and achieve commercial operation by October 15, 1971.
Based' on observations of work in progress and the f act that no pre-startup tests have yet been performed, August or September seens more likely than July for fuel loading.
230'KV Transmission Three sets of outgoing 230 KV lines have been erected and renamed. The former " North Greenville" lines are now the "Dacus" lines.
The adjacent pair of " Central" lines have been renamed j
"Oconee" and the other pair of " Central" lines have been renamed j
the "Calhoun" lines. _ Although the two lines northwest to
~Jocassee are not scheduled for completion until 1974 the onsite bases for its towers were being prepared during our visit.
We also noted that the right-of-way for this line has already been cleared and graded to beyond the 1 mile exclusion crea boundary.
500 KV Transudssion Except for grading of the switchyard area, no site work has been completed on the 500 KV transmission system.
This system is intended to be available f or use with Unit 3.
Control Ro'd Drive System We examined the ability to monitor the withdrawal position of
- each of the 69 control rods in the control room.
Two means of
- display are availabic (1) a bank of 69 separate panel meters each capable of monitoring either the relative or absolute withdrawal position of one rod, and (2) a CRT display f rom the plant computer which can also provide either relative or absolute withdrawal position information for all 69 rods.
- We observed that the meters display rod positions by groups (after patching) and not by core-position (i.e., it a rod is changed from one group to another by reprogramming the patch
- panel connections, its positions will be read out on a dif ferent meter af ter reprogramming).
One must therefore infer core position of that rod from other information.
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3 R. C. DeYoung It was explained (but could not be demonstrated due to state of installation progress) that the CRT display f rom the plant computer was on the basis of core position, with each readout being numbered 1.through 69.
It was further stated that the wiring from each 'of the 69 absolute position indicators (reed switches mounted on the control rod drive assembly housing and magnetically activated by actual control rod drive mechanism movement) and from each of the 69 relative position source points (a pulse-stepping motor which is stepped only by the particular de pulses which drive a par ticular control rod drive mechanism) are " hardwired" direct to the computer which provides the CRT output display in the control room.
Based on our observations and knowledge of this system, it j
therefore appears that the control room operator will know j
control. rod withdrawal position based on core position indepen-dent of reprogramming activities in the patch panel.
One area of concern remains, however.
The "hardwire" connections for both relative and absolute indications are disturbed every time the reactor head is removed.
To remove the head all power and instrumentation cables to all 69 rod drives are disconnected.
This is a potential problem area that we need to examine further te be sure that adequate precautions can and will be taken to prevent or detect, and correct errors in reconnecting these cables.
Cranes and lloists in the Reactor Building T? ere are two features of load handling equipment which are not properly covered in the FSAR.
The FSAR (Figura 9-11.& pp 9-36, 37) shows a polar crane, a main (two-hoist) feet handling bridge and an auxiliary (one-hoist) fuel handling bridge.
Actually there are two identical two-hoist fuel handling bridges and a control rod drive housing handling bridge and a polar crane. The applicant stated that the two fuel handling bridges are identical to permit continued refueling operations in the evei.t one bridge should break down. The (new to us) rod drive housing handling bridge, mounted atop the two steam generator compartment inboard walls, is intended to be used to remove-an individual control rod drive housing without removing the reactor pressure vessel head.
I indicated that the FSAR should be corrected to show the actual equipment being installed and that the Tech Specs on fuel handling will have to place restrictions on the use of this bridge as well as on the use of the polar crane.
I
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t 4y R. C. DeYoung-4 Minimum Dilution Flow
- Seepage from the, base of the Keowee' Dam (with Lake Keowee now sat: spillway level) was essientially the scroll-of one. of the hydro units, the leakage i t nonexistent.
From inside tunnel from. Lake Keowee was.also very small.
n o the conditions, it is doubtful that, with ~ the Hydro Station Tunnel -
Given these dewatered '(as itl is at present). anything like 30 CFS of dilution water will be available to the tailrace for mixing with radi Lactive waste discharge. unless the emergency dis h o-c arge conduit is used.
Containment Auxiliary Ventilation An interesting observation 'inside the reactor building
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the distribution of the auxiliary ventilation syste
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was (which is not well' described in the FSAR).m ducting polar crane rail and additional ducting extends upa Intake ducts underside of the ' dome. -
cross ventilation' just above the refueling canal levelIn addition auxiliary ventilation system is separate from the emergen Ihis fan ' cooler units.
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. J :' T A. Schwencer PWR Project Branch No.
2 Division of Reactor Licensing Dis tribution:
Docket file ;(50-269)-
-DRL' Reading
- PWR-2 Reading
SHanauer-
. PAMorris FSchroeder -
'-TRWilson RWKlecker
' ECCase, DRS Compliance (2)
MHildreth,. CO.
- .CMurphy, CO. Region II
- V. A.~ Moore p
KGoller-i DMuller.
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1 OCONEE NUCLEAR STATION SITE VISIT Feb ruarv 11 and 12, 1971 Attendance List AEC A. Schwencer, DRL j
- 0. D. Parr, DRL V. A. Moore, DRS I
F. Rosa, DRS S. H. Hanauer, DR (February 12)
C. Murphy, CO Region II Duke Power Company _(Partial listing),
Bill Parker Paul Barton Charles Wylie Warren Owen Everett Gladden Ken Canady Ed Smith Ollie Bradham J. C. Rogers Carl Price Bill Foley Peter llager Charles Aycock Kyle Burris Jim Hampton B&W (Partial listing)
Caorge Kulynych Howard Stevens E. S. Patterson
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