ML25013A009
| ML25013A009 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 01/13/2024 |
| From: | Morgan M SONGS Decommissioning Solutions |
| To: | Southern California Edison Co |
| References | |
| Download: ML25013A009 (1) | |
Text
1 SONGS Decommissioning Lessons Learned Mark Morgan Manager, SONGS Nuclear Regulatory Affairs
2 SONGS Decommissioning - Lessons Learned
- Topics
Public Engagement
Pressurizer Shipments
Groundwater Tritium
3 Public Engagement
- Community Engagement Panel (CEP)
Created in 2014 (one year following shutdown)
Varied panel membership includes elected officials, environmental groups, union representative and others Quarterly meetings - different focus each meeting Variable attendance over time
- Early broad curiosity in decommissioning and regulatory framework
- Continued interest in issues related to storage, transport and removal of fuel from the site
- SONGS website - Songscommunity.com Information regarding decommissioning status, storage of spent fuel, strategic plans for removal of fuel, and more
4 Public Engagement
- Speaking Engagements
- Tours - Significant public interest in SONGS tour program
- 2024 81 speeches and tours 1329 guests
5 Public Engagement - Lessons Learned
- The value of person-to-person interactions
- Leverage representatives (employees/3rd party speakers) with a depth of knowledge
- Community Engagement Panel is a big undertaking Build a diverse and independent panel Arranging for third-party speakers Securing venues Technology issues
6 Unit 2 Pressurizer (PZR) Leak During Transit to Clive Utah for Disposal On 6/30/24, while the Unit 2 and 3 PZRs were parked in a rail yard located in San Bernardino, a leak from the Unit 2 PZR manway was identified by a rail worker Conservatively estimated up to 3 liters may have leaked)
A SONGS Radiation Protection Team was promptly mobilized to San Bernardino to perform radiological surveys, cleanup, and stop the leak No leakage was identified from the Unit 3 PZR On 7/4/24 both PZRs were returned to the SONGS site for cause investigation and corrective actions to prevent reoccurrence Unit 2 & 3 PZRs prior to departing SONGS on 6/27/24 and 6/29/24, respectively
7 Unit 2 PZR Leak Radiological Surveys
- Results of Radiological Surveys Leak limited to top of rail car (no water escaped the rail car)
Surveys found no readings above background radiation levels on or around the rail car No risk to public health Water was reactor coolant that remained in the U2 PZR after the primary system was drained
- Reported issue in accordance with 10 CFR 50.72 based on interaction with a public agency (California Office of Emergency Services)
- PZRs were manifested as sealed and dry packages per NRC and DOT regulations
- NRC issued SCE two Severity Level IV (lowest level) Non-Cited Violations One for a package that was not leak tight, and another because the package should have been dry but contained liquid
8 Unit 2 PZR Leak - Investigation Findings Unit 2 PZR thermal sleeve weep holes unexpectedly blocked leading to retention of 190 gallons1 of water after the RCS system was drained Unit 3 PZR was dry (weep holes not blocked)
Workers assumed that the PZRs were drained prior to waste packaging based on configuration of the RCS system Workers assumed the PZR manway gaskets remained in place after SONGS entered decommissioning in 2013 Higher ambient temperature in San Bernardino (as compared to the SONGS coastal region) increased the internal pressure of Unit 2 PZR, causing water to leak though the manway studs U2 PZR Internal Configuration PZR Installed Configuration Note 1: 190 gallons is approximately 1% of the 16,500-gallon capacity of the PZR.
9 Unit 2 PZR Leak - Lesson Learned
- Ensure that critical assumptions are verified
10 Unit 2 Groundwater Tritium (H-3)
- Tritium is produced during reactor operations and is a known issue for decommissioning plants Found at SONGS U1 during decommissioning and remediated
- During routine quarterly sampling, H-3 was detected in groundwater monitoring well in April 2024 (sample results received in June 2024)
- H-3 not detected in other monitoring wells
- Sampling for H-3 of a nearby non-radiological well in August 24 found even higher concentrations of H-3
- Monitoring trend in H-3 bysampling PA-2 and MW-8 every other week
- NRC notified in August 24
- SCE made NEI 07-07 GPI voluntary communication to federal, state, and local agencies and stakeholders in September 24
- SCE has engaged a hydrogeologist to support thorough investigation of H-3 plume and to identify the source
- Groundwater beneath SONGS is not a source of drinking water
11 Unit 2 Groundwater Tritium (H-3) Investigation Sampling on 12/5/24 of monitoring well MW-8 indicates a downward trend in H-3 concentration while PA-2 H-3 concentration remains stable Sampling of three non-radiological monitoring wells located north of Unit 2 did not detect H-3 Installation of six new wells in vicinity of PA-2 and MW-8 to determine extent of H-3 plume started in January of 2025 New wells sampled and analyzed this month
12 Unit 2 Groundwater Tritium (H-3) - Lesson Learned
- Proactive reporting of even low-level issues and communication with the public promotes confidence in the decommissioning project.
13 SONGS Decommissioning - Lessons Learned Questions