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April 28,1986 MEMORANDUM FOR:
H. L. Thompson, Jr., Director, Division of Pressurized Water Reactor Licensing-A, NRR FROM:
Jack A. Hind, Director, Division of i
Radiation Safety and Safeguards, Region III
SUBJECT:
REQUEST FOR TECHNICAL ASSISTANCE REGARDING POST-ACCIDENT NOBLE GAS EFFLUENT MONITORING SYSTEMS AT CALLAWAY
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During a recent inspection of the Callaway County Nuclear Station, the f
inspectors noted that some of the installed post-accident noble gas effluent 7
systems and the associated technical specifications appear contrary to regulatory positions. These items concern the technical adequaty of installed q
radiation detectors to monitor the post-accident main steam safety relief a
valves / power-operated relief valve (PORV) pathway and the apparent discrepancy between Callaway Technical Specifications 3.3.3.6 and 4.3.3.6 and regulatory positions stated in Generic Letter 83-37. Details regarding these items are attached.
We request that you provide us guidance concerning the acceptability of the above licensee installations and technical specifications.388-5261)gionIII The Re technical contacts for this matter are Charles Gill (FTS or L. Robert Greger (FTS 388-5644).
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- Nack A. Hind,. Director Division of Radiation Safety and Safeguards
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Attachment:
As stated cc w/ attachment:
P. O'Connor, NRR R. Bellamy, RI e
D. Collins, RII R. Hall, RIV F. Wenslawksi, RV C. Norelius, RIII Resident Inspector qgi.
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l ATTACHMENT Fain Steam PORV_ Plume Radiation Monitors i
During the revie4 of the post-accident noble gas effluent monitoring s the main steam safety relief valves / power-operated relief valve (PORV)ystem for
- pathway, the inspectors nated that the technical adequacy of the licensee's installed radiation monitor!. was questionable. The radiation monitors are located on the auxiliary building roof and oriented, shielded, and co111 mated to detect the plume from the PORVs.
If the PORVs are blocked, the radiation monitors appear incapable of responding to post-accident main steam release via the safety relief valves. The PORVs are not code safety valves and are presently not governed by the technical specifications; thus, the licensee may operate the plant with blocked PORVs without restriction. Also, in accident circumstances the licensee may elect to block leaky PORVs to prevent the release of radioactive effluents and/or the loss of secondary system coolant. The inspectors informed the licensee that the acceptable location for externally mounted monitors specified by NUREG-0737, Item II.F.1, Attachment 1 is on the main steam line upsteam of the safety valves and PORV and that NRR is presently evaluating a similar technical issue at the D. C. Cook Nuclear Power Plant (Inspection Reports Nc. 50-315/85011; 50-316/85011, Unresolved Items No. 315/85011-05; No. 316/85011-04).
Technical Specifications 3.3.3.6 and 4.3.3.6 During the review of the licensee's commitments to NUREG-0737, Item II.F.1,, the inspectors noted that the installed post-accident noble gas effluent radiation monitors were apparently those described in Appendix 7A and Subsection 18,2.12.2 of the FSAR. The post-accident noble gas effluent radiation monitors identified in the f5AR are used to monitor effluents from the plant unit vent, the radvaste building, the main steam PORVs, and steam discharge from the turbine-driven auxiliary feedwater pump.
Generic Letter 83-37, "PWR NUREG-0737 Technical Specification," dated November 1, 1983, specifies that all of the licensee identified post-accident noble gas effluent radiation monitors should be included in the accident monitorino technical specifications; however, Callaway Technical Specifications 3.3.3.6, " Accident Monitoring Instrumentation Limiting Condition for Operation," and 4.3.3.6,
" Accident Monitoring Instrumentation Surveillance Requirements," include only the plant unit vent high range noble gas monitor.
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