ML113400006
| ML113400006 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 11/10/2011 |
| From: | Operations Branch I |
| To: | Dominion Nuclear Connecticut, Dominion Resources |
| JACKSON D RGN-I/DRS/OB/610-337-5306 | |
| Shared Package | |
| ML102850247 | List: |
| References | |
| TAC U01834, 50-336/11-301 | |
| Download: ML113400006 (15) | |
Text
Page 1 of 15 Post Exam Comments on RO Question #61 Facility Comments
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Page 15 of 15 NRC Response The NRC agrees with the proposed change. RO Question #61 has TWO correct answers. Both Answers B and D will be accepted as correct.
A pressurized water reactor operating in its power range responds via temperature feedback mechanisms to a change in steam demand on the secondary plant. When operating with a negative moderator temperature coefficient, the feedback causes reactor power changes that trend toward restoring equilibrium between heat added to the reactor coolant system and heat removed from the reactor coolant system. Question #61 describes a situation where secondary steam demand is reduced. The reduced steam demand will raise SG pressure. RCS cold leg temperature and average coolant temperature will both increase. The higher temperature water passing through the reactor vessel will add negative reactivity, lowering reactor power generation, as indicated on nuclear instruments and also on delta-T power instruments, where delta-T power is proportional to the difference between hot and cold leg temperatures.