ML23320A237
| ML23320A237 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 11/08/2023 |
| From: | Saporito T Nuclear Energy Oversight Project |
| To: | John Lamb Plant Licensing Branch II |
| References | |
| Download: ML23320A237 (5) | |
Text
From:
Nuclear Energy Oversight Project <NEOP@gmx.com>
Sent:
Wednesday, November 8, 2023 9:14 AM To:
Subject:
[External_Sender] Re: Vogtle Mr. Lamb, Per your request, here are the concerns that I brought to the attention of the NRC during the conference call as best that I can recall - and maybe some additional concerns:
The licensee stated that one of the reasons for submitting the LAR to the NRC was because of a concern that the 2nd EDG would not automatically start as required. The licensee further stated that there was air leakage from the air-start supply as designed and that there was sufficient air-start supply for 5-attempts to start the EDG.
NEOP concern: there appears to be a licensing issue here where the licensee's FSAR and NRC regulations require that both EDGs be able to automatically start during an emergency situation.
On page 18 of the licensee's slides, they state, in relevant part, that "Updated analyses show that there is sufficient fuel oil to meet the 7-day requirement provided operator actions reduce electrical load on the EDGs.
An EDG loading profile will need to be used to achieve the 7-day requirement, which will involve changes to operating procedures.
NEOP concern: To the extent that the licensee's operators would take actions to reduce the EDG electrical load, this causes concern about taking "safety related" equipment off the power bus of the EDG since that is the basic function of the EDG to supply power to safety related equipment. The licensee does not appear to have adequately performed a fault-tree analysis to ascertain what safety related equipment and/or systems would be adversely affected with the proposed LAR - and whether taking safety-related equipment off the power bus would adversely affect the safety of the nuclear reactor.
The licensee's proposed LAR reduces the Regulatory Guide 1.27 mandate which requires that "The capacity of the UHS should be sufficient to provide cooling for the time necessary to evaluate the situation and take corrective action. A period of 30 days is considered adequate for these purposes. In addition, procedures should be available for ensuring the continued capability of the UHS beyond 30 days.
The licensee's LAR requests NRC approval to depart from the mandates of Regulatory Guide 1.27 and to reduce the 30 day requirement down to a 22 day requirement. The licensee's justification for this departure is merely an assumption and a "guess" that 22 days would be sufficient for the licensee to evaluate the situation and take corrective action.
NEOP concern: To the extent that the licensee would have only 22 days to evaluate an emergency situation and take corrective action - NEOP suggests that the licensee's assumption is incorrect and not based on the licensee's operational history of dealing with a nuclear emergency such as a LOCA or other
such general emergency. To this extent, the NRC should require further justification from the licensee with written examples along with operational procedures of exactly how the licensee operators would take actions to evaluate and take actions during any emergency situation. NEOP notes here that the Three Mile Island, the Chernobyl, and Fukushima nuclear accidents all resulted in a reactor core melt-down which took the respective plant operators more than 30 days to evaluate and take corrective actions to protect the health and safety of the public and to protect the environment. NEOP notes here that in those situations, the environment overall was not sufficiently protected from the release of radioactive particles.
The licensee stated that: Well Water Makeup: Normal makeup water for the nuclear service cooling water is provided by wells drilled into the Tuscaloosa aquifer, which has enough water yield capacity to meet the makeup requirements for emergency conditions... The well water pumps are not powered by safety related buses. However, their power supplies are tied to Station Auxiliary Transformers (SATs). These SATs are connected to Plant Wilson, which can provide support through black start diesel generators to provide power to the Well Water pumps. See, LAR Id. @ p21.
NEOP concern: To the extent that the licensee intends to draw make-up water from wells that incorporate pumps that are NOT connected to the safety related buses from Vogtle EDGs - the licensee cannot provide reasonable assurance that the requirements of Regulatory Guide 1.27 will be fully complied with and that power to the well pumps would be available on a 24/7 day basis. Moreover, the licensee thus far has failed to demonstrate that there exists adequate surveillance procedures for the well pumps, including periodic maintenance procedures, valve alignment procedures, etc. In addition, the licensee thus far has failed to demonstrate that there are procedures regarding drawing power for the well pumps from Plant Wilson. Additionally, the licensee thus far has failed to demonstrate whether or not Plant Wilson has sufficient electrical power capacity to handle the additional current draw from the well pumps.
Also, the licensee thus far has failed to state exactly what they mean by "Plant Wilson"? Does the licensee mean that the EDGs at Plant Wilson would supply power - or does the licensee mean that power from Plant Wilson's electric grid would supply power? In any event, NEOP maintains that any power source relied upon by the licensee to supply power to the well pumps must come from a "safety related" power bus energized by EDGs that auto-start during an emergency situation. The cumulative concerns delineated above are intended to also address the licensee's intent to draw make-up water from the river. See, LAR @ p.22.
As stated above, the licensee intends to draw make-up water from wells and from the river.
NEOP Concern: the licensee should be required to have operating procedures to address valve alignments and surveillance requirements.
NEOP concern: the licensee should be required to address seismic concerns related to the wells and to Plant Wilson to provide reasonable assurance that a
seismic event would not otherwise disrupt the availability of the well pumps or the river pumps or power supplied from Plant Wilson.
The licensee's proposed basis and justification for the LAR is that: The proposed configuration will allow for both EDGs and NSCW trains to remain in operation after the first 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> post-accident.* This change would reduce the inventory of the NSCW cooling tower basin from 30days to 22 days* After 22 days post-accident, available makeup cooling water would be utilized from the sources, well water and river water makeup system, to ensure there is sufficient water available to the equipment serviced by the NSCW cooling towers.
- The proposed configuration continues to ensure cooling water is available 30 days post-accident, using backup system replenishment in accordance with Regulatory Guide 1.27." See, LAR @ p.12.
NEOP concern: the licensee's LAR taken as a whole involves a major departure from the mandates of Regulatory Guide 1.27 and the licensee's FSAR and UFSAR. Moreover, as stated above, the licensee intends to provide make-up water during an emergency situation to the basins using power supplied to pumps at wells and at the river - from NON-SAFETY RELATED power buses. In addition, the licensee has failed to provide reasonable assurance to the NRC that the LAR would enable the licensee to operate Plant Vogtle in full compliance with NRC regulations and requirements. (i.e. technical specifications, FSAR, UPFSAR, safety related power busses, operating procedures, EGD operational availability etc.)
NEOP suggests: that the licensee should reconsider seeking NRC approval of the LAR - and instead - install a 3rd EDG employed for the sole purpose of supplying make-up water from the wells and from the river as outlined in the proposed LAR.
Should you have any questions regarding the above, please do not hesitate to contact me at your convenience.
- Regards, Thomas Nuclear Energy Oversight Project Thomas Saporito Executive Director 6526 S. Kanner Hwy. Unit 235 Stuart, Florida 34997 Phone: (772) 262-0728 Email: NEOP@gmx.com On 2023-11-08 7:40 AM, John Lamb wrote:
Mr. Saporito, At yesterdays meeting, you provided your concerns on the proposed LAR regarding the ultimate heat sink at Vogtle, Units 1 and 2. I took notes as best I
could, but it would be helpful if you could email me your concerns so I can capture them accurately in the meeting summary.
Thanks.
John From: Nuclear Energy Oversight Project <NEOP@gmx.com>
Sent: Tuesday, November 7, 2023 12:57 PM To: John Lamb <John.Lamb@nrc.gov>
Subject:
[External_Sender] Vogtle Mr. Lamb When you have time, could you please provide the NRC ML "Access Number" for the NRC NOV for Vogtle regarding the EDG which lead to the licensee's recent LAR regarding the UHS? I must have written down the wrong number.
Thanks!
Thomas Nuclear Energy Oversight Project Thomas Saporito Executive Director 6526 S. Kanner Hwy. Unit 235 Stuart, Florida 34997 Phone: (772) 262-0728 Email: NEOP@gmx.com
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[External_Sender] Re Vogtle Sent Date:
11/8/2023 9:14:01 AM Received Date:
11/8/2023 9:14:17 AM From:
Nuclear Energy Oversight Project Created By:
NEOP@gmx.com Recipients:
"John Lamb" <John.Lamb@nrc.gov>
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