ML19317G476
| ML19317G476 | |
| Person / Time | |
|---|---|
| Site: | Crystal River  |
| Issue date: | 12/09/1975 |
| From: | Schwencer A Office of Nuclear Reactor Regulation |
| To: | Rodgers J FLORIDA POWER CORP. |
| References | |
| NUDOCS 8003160088 | |
| Download: ML19317G476 (5) | |
Text
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DISTRIBUTION:
NRC PDR PF L PDR bec: JRBuchanan,0RNL Docket No.:
50-302 Docket Fue TBAbernathy,DTIE r g,,
G75 LWR 2-3 Rdg VAHoore RHeineman UMcDonald Florida. Power Corporation LWR TC's ATTil: Mr. J. T. Itodgers ELD Assistant Vice President IE(3)
& Nuclear Project Managar LEngle P. O. Box.14042 EGoulbourne St. Petersburg, Florida 33733 TR BC's
ACRS (16)
TIC We find that additional inform.ation is needed to complete our review of the ECCS analysis for Crystal River, Unit 3 (CR-3). The requests for information are provided in the enclosure to this letter.
Our current review is based on your submitted ECCS analysis for CR-3.
In addition to topical report 3AW-10103, "ECCS Analysis of BMl's 177-FA Lowered Loop NSS," we are evaluating the contents of your letters dated Septenter 19, 1975 and October,197C.
Some requests for infornation have aircady been sent to BT,1 partaining to BAW-10103.
Uc request your response to the enclosure be sent to us by January 5,1975.
The response date is necessary so that our review and conclusions of the CR-3 ECCS analysis can be incorporated in a supplement to the SER.
Thi::
supplement is presently scheduled for issuance on M ruary 3, 1976.
If you cannot meet the response date, please infcr es within seven days after receipt of this letter.
Please contact us if you have any questions regarding the enclosures
,rovided.
Sincerely,
- ppm [I
~
A. Schwancer, Chief Li';ht Watar Reactors Cranch 2-3
' Division of T.eactor Licensin:
Enclosure:
Request for ECCS Information-g 7-W f
-cc: See next'page
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g ""ST FOR ADDITIONAL INFORMATION CRYSTAL RIVER 3 1.
. With regard to the potential for boron precipitation:
a)
Page 2 of Florida Power Corporation's letter indicates that the vulnerability of dilution ~ Modes I, II, III, and IV to single failures is analysed in Section 10 of Topical Report BAW-10103.
Further information is needed from Florida Power to confirm th single failure position stated in BAW-10103.
It is the staff's position that Mode I should not be attempted as the primary method to ' control boron concentration in the core during long-term cooling.
The possibility of gas or steam entrainment in the decay heat suction nozzle can result in severe damage to the decay heat removal pump.
Long-term heat removal requirements can exist for bng durations (days or monens) after the accident and continuous operation of one train of the decay heat removal system is required.
In the event of an equipment malfunction in this train,.no method is available to remove the decay heat if the other train has been previously damaged.
Therefore, implementation of Mode I should not be attempted since this action could result in the decrease of required safety equipment.
Since initiation of Mode I is not allowed, it must be established that Modes II, III, and IV in combination are single failure proof.
An alternate to consider is the feasibility of utilizing a single mode, with modifications to make this mode single failure proof and relatively free of pump cavitation problems.
We suggest you examine the possibility of maintaining containment sump suction for the LPI pu=ps, while utilizing gravity drain to the containment sump.
achieve this drainage, small lines may have to be installed from To the DliR drop line to the containment sump (with suitable motor
-operated isolation valves).
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b)
Provide the specific operating procedures required 'to implement each of these dilution modes.
Indicate each operator action necessary, and identify which valves must be manually operated outside the control room.
Confirm the capability for the operator to close or open these valves at l
the time specified in the Septembe'r 19th letter (to be instituted i
l
' 15 minutes af ter a LOCA) and evaluate the radiation levels which could be present at the valve locations.
c) _ Florida. Power Corporation indicates that a backup electrical i
supply,is present to run the pumps and actuate the motor-driven valves for all modes in case of electrical failure (see reference j
to BAW-10103).
List all pumps and valves included in the dilution modes with their associated power supplies.
Specify their power-requirements and relate to the capacity of the backup pouer supply.
=-
Indicate the location of-this power supply in the plant.
Specify those motor-operated valves in the dilution modes which, if rendered inoperable due to a common power supply failure, would fail all-dilution modes.
Discuss your means to connect power to these valves should they be P side containment.
d)
Confirm that remote readouts of dilution flow rates for each mode are available in the control room, e)
Discuss the capability to test the dilution modes.
f)
Explain the type of valves that DHV-39 and DHV-40 are, and identify.their mode of actuation.
g)
Provide the elevations of the piping and other components in the decay heat drop line from the hot leg nozzles through each of the trains to the reactor building sump. This infor-mation will verify that gravity draining for boron dilut' ion for Mode II is possible.
h) Mode III:
Justify the 40 gpm predicted to occur through the auxiliary pressurizer spray line.
Since water is being pumped from the containment floor,. discuss the' ability of the spray to pass all material admitted through the sump screens.
1)
Indicate the feasibility-of monitoring boron concentration levels during the long term.
2.
With' regard to the single failure analysis; a)
Confirm that a single failure or operator error that causes any motor-operated valve to inadvertantly actuate could not adversely affect the ECCS (i.e., Service Water System Valves, Building Spray System Valves, Boron Dilution Valves, CFT Vent Valves, etc.).
b)
F. ovide a. list of each valve considered under item a) and indicate the consequences of the spurious actuation.
c)
FSAR Figure 9-6 shows LPI valves DH-V4A and DH-V4B to be normally closed.
To allow low pressure injection subsequent to a CFI line break and a single active component failure,-these valves must be required by Station Technical Specifications to be open, power removed, and breakers locked open.
Station Technical Specifications must also require a periodic test be performed to warn of abnormal leakage of the check valves in the LPI injection lines inside contair. ment and that this test be performed at least annually.
These changes provide assurance that abundant core cooling is
.av,ailable for a CFT line break and further minimize the. potential for a LOCA outside containment.
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3.
It is noted that motor-operated valves DH-5A and DH-5B from the BWST are shown normally closed. It appears that, assuming sufficient static head were available, the potential for a water hammer when ECC is injected into a dry line w'uld be reduced o
considerably if these valves were normally left open.
Please discuss.
Also, confirm that periodic venting of ECCS lines and ECCS pump casings are performsf and reference this surveillance requirement in your station technical sp'ecifications.
4.
With regard to the potential for submerged valves, the September 19th letter indicates that there are no valve motors which would be flooded that are required to operate following a LOCA. Provide the level of water assumed after the LOCA. Provide the elevation of the motors for DER suction valves DEV1, DHV2, and DHV3.
Confirm that any other equip-ment essential to ECCS performance which could be submerged would not be adversely affected.
5.
With regard to the partial loop analysis (Reference to BAW-10103):
Tech'nical Specifications will prohibit 2-p. ump operation unless an analyses is provided to support this mode of operation.
Compare a break in the inactive cold leg to a break in the active cold leg.
b)
Provide assurance (other than historic extrapolation) that the PCT versus Break Size curve in BAW-10103 would not be significantly altered by either mode of partial look operation.
c) Submit the LOCA parameters of interest identified in the "Minimus Requirements for ECCS Break Spectrum Submittals,"
dated April 25, 1975.
d)
The analysis states that the peak linear heat rate for the hot
~
bundle is the maxi =um kw/f t LOCA limit as shown in Figure 2-2 of BAW-10103 at the six-foot elevation for this mode of operation.
Clarify the effect of such an assumption on Station Technical Specifications.
If this assumption would allow 3-pump operation at this kw/ft, discuss the consequences of the abnormal events in Chapter 15.0 should they occur during three (or two) pump operation.
6.
Pr$ vide your schedule-for submitting revisions to the proposed Technical Specifications affected by the LCCA analysis.
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