ML20134M255
| ML20134M255 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 02/14/1997 |
| From: | Cruse C BALTIMORE GAS & ELECTRIC CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9702200163 | |
| Download: ML20134M255 (4) | |
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'9 Curates II. CROSE Baltimore Gas and Electric Company Vice President Calvert Cliffs Nuclear Power Plant Nuclear Energy 1650 Calven Cliffs Parkway Lusby, Maryland 20657 410 495-4455 February 14,1997 U. S. Nuclear Regulatory Commission Washington, DC 20555 ATTENTION:
Document Control Desk
SUBJECT:
Calvert Cliffs Nuclear Power Plant Unit Nos.1 & 2; Docket Nos. 50-317 & 50-318 Request for AdditionalInformation: Criticality Monitoring License Exemption Request
REFERENCES:
(a)
Letter from Mr. C. H. Cruse to NRC Document Control Desk, dated August 19, 1996, License Exemption Request:
Exemption from Criticality Monitoring Requirements In response to verbal NRC staff questions, Baltimore Gas and Electric Company is providing the additional information requested. The information is provided in Attachment (1).
Should you have additional questions regarding this matia, we will be pleased to discuss them with you.
Very truly yours,
- d ere "
,,yg,
CIIC/JPW/ dim Attachment (1)
Baltimore Gas and Electric Company's Response to NRC's Request for Additional Information Concerning License Exemption Request: Criticality Monitoring Requirements cc:
D. A. Brune, Esquire II. J. Miller, NRC J. E. Silberg, Esquire Resident inspector, NRC
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Director, Project Directorate I-1, NRC R. I. McLean, DNR A. W. Dromerick, NRC J. H. Walter, PSC 9702200163 970214 PDR ADOCK 05000317 P
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ATTACHMENT i
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j BALTIMORE GAS AND ELECTRIC COMPANY'S RESPONSE TO NRC'S REQUEST FOR ADDITIONAL INFORMATION CONCERNING i
LICENSE EXEMPTION REQUEST: CRITICALITY MONITORING REQUIREMENTS i
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j Calvert Cliffs Nuclear Power Plant February 14,1997 1
ATTACHMENT (1)
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BALTIMORE GAS AND ELECTRIC COMPANY'S
' RESPONSE TO NRC'S REQUEST FOR ADDITIONAL INFORMATION CONCERNING LICENSE EXEMPTION REQUEST: CRITICALITY MONITORING REQUIREMENTS Ouestion 1:
Discuss thepossible sources ofwater duringfuel handling and storage.
Respansci The possible sources of water during fuel handling and storage are normally isolated and include:
1.
Fire stations HS-69-4 and HS-69-6. Each fire station can provide approximately 2,500 gpm of water from two 500,000 gallon plant service water tanks.
2.
Plant service water isolation valves 0-PSW-140,0-PSW-139, and 0-PSW-251: These are low flow rate systems, which also take suction on the two 500,000 gallon plant service water tanks.
3.
Demineralized water isolation valves 0-DW-302 and 0-DW-190: These are low flow rate systems, which take suction on the 350,000 gallon demineralized water storage tank.
4.
Plant heating system valve 0-PH-281: This is a low flow rate system, which also takes suction on the two 500,000 gallon plant service water tanks.
5.
400,000 gallons of borated water from each refueling water tank could be inadvertently supplied to the spent fuel pool, via the Spent Fuel Pool Cooling System.
No fire protection sprinkler system exists in the new fuel handling area.
Question 2:
Discuss the procedural controls that are imposedfor precluding inadvertent criticality offresh fuel duringfuel handling, inspection, and movement prior to storage in thefreshfuel racks.
Response
In order to achieve criticality of new fuel, a specific fuel assembly geometry must be achieved and sufficient neutron moderator (water) must be available. As described below, our procedures do not permit the required fuel assembly geometry and neutron moderation necessary to achieve criticality.
Specific procedural controls for the handling and inspection of new fuel are contained in procedure Fuel Handling (FH)-301, Core Component Receipt Inspection. In addition to requiring pre-job briefing and training, the procedural controls include:
1.
Plastic bags or other dust covers placed around new core components are removed or rendered incapable of holding water prior to inserting the assemblies into the new fuel storage racks. Therefore, water cannot accumulate in or around the assemblies.
2.
Only the auxiliary hook of the spent fuel cask handling crane may be used to move new fuel.
Therefore, only one fuel assembly can be moved at a time.
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ATTACHMENT (1)
BALTIMORE GAS AND ELECTRIC COMPANY'S
' RESPONSE TO NRC'S REQUEST FOR ADDITIONAL INFORMATION CONCERNING LICENSE EXEMPTION REQUEST: CRITICALITY MONITORING REQUIREMENTS 3.
A maximum of two fuel assemblies are permitted outside of the approved shipping container or new fuel storage rack location at a time. In addition, one of these two assemblies must be located in the new fuel inspection platform. Ahhough our analysis indicates that it is possible for two fuel assemblies to achieve criticality under specific conditions (close proximity, 4
maximum fuel enrichment, fully flooded), it is not conceivable that the required neutron moderation (water level) could be attained. Assuming one fuel assembly is located in the new fuel inspection platform (vertical configuration) and a second assembly was moved next to it, the spent fuel pool area and new fuel handling areas would have to be flooded to an elevation approximately 17 feet above the floor. Achieving this fully flooded condition from 4
the above low flow rate sources (refer to Question I response) would require blockage of floor drains, sealing of access doors, and numerous procedure violations. Finally, the spent fuel pool high level alarm will alert operators of flooding from the above sources.
_ Question _31 Verify that radiation monitoring remains available to meet the requirements of General Design Criteria 63forfuelstorage areas.
E_csaanse:
Three area radiation monitors are provided for detecting high radiation levels in the fuel storage areas.
The monitors are located in the Spent Fuel Pool Area, the Spent Fuel Handling Machine, and the New Fuel Storage Area. Each monitor contains a gamma sensitive Geiger-Mueller tube and has an indicating range of 10" to 10' Rem per hour. The Spent Fuel Pool Area and New Fuel Storage Area monitor alarm 4
setpoint is 5 x 10 Rem per hour, while the Spent Fuel Handling Machine monitor alarm setpoint is 1 x 10-2 Rem per hour. At the alarm setpoint, audible and visual alarms annunciate locally and in the Cantrol Room. The output ofeach monitor is also recorded in the Control Room.
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